Assuming you're playing the Allies, here are my recommendations. I used this in the 1943 Grand Campaign Additional Air HQ, but you should get the idea.
Fighter Command - Set up three Air Superiority AD's from Bradwell Bay, Hawkinge, and Southend, each with 12 of your best EXP air groups. 90 gallon tanks on each. Fly them in overlapping size 4 areas over Holland and Belgium. Rest half the groups during the Friendly turn and the other half during the Enemy turn. Fly them all days, both air Phases, at 24K'. They will kill many of the German interceptors going for your bombers, particularly in the first few turns.
Bomber Command - on turns 1 and 2, fly night Strategic bombing missions against the U-Boat factories so you get rid of those negative VP targets. (That means you need to recon them first, remember to pick "Strategic" and then the correct Target type.) I fly a size 5 AD with Schulau as the target. Even though there are no UB factories there, the size-5 box covers Hamburg, Bremen, Bremerhaven, Kiel, and Luebeck. Swap out Stirlings for Lancasters, which can carry 14 1000 bombs, which are best for this work, and fly at 23K'. Ultimately swap out the Halifaxes also. Include at least 320 bombers and set Strike Number to 5 and Req AC to 64 each. Use other AD's to target Wilhelmshaven, Emden, and Flensburg. If you decide to hit Danzig, you need to change the Lancaster loadout to 6x1000 lb bombs and the extra fuel tanks.
Fly the big size 5 AD on days 2/4/6, and the single missions, particularly the Danzig raid, on days 3/5/7. You want to fly different air groups every day so the Germans have to fly every day.
Night Fighters - On turn 1 set up some size 6 night intruders AD's over various parts of Germany, France, and the Lowlands. German NF's tend to be around Hamburg and the Ruhr. Put two NF air groups in each AD, set to Friendly Air Phase only, fly 1/2/3/4/5/6/7, 21K', 12 Req AC. Make sure you set the AD to Night. If you look at the Shift-d Air Directive Summary after the air phase, you can see where your Night Intruders shot down enemy NF's. These are where the German NF bases are. Then in Turns 2 and onward, fly size 0 Night Intruder missions against those bases, each with two NF air groups and 12 Req AC. Some might think this is gamey, but I figure Allied NF's returning from missions would report where they caught German NF's landing.
8th Air Force - If you're playing the 1943 campaign, the only escorts you have are some P-38G/H's, and short-range P-47D-5's. Set up a Strategic bombing AD that targets Emmerich Fuel and Manpower. Assign our lowest EXP B-17F group, and all your P-47 groups to it. Fly it days 1/3/5, altitude 24K. Set Req AC to 48/360. The way the German AI works is that it will intercept with roughly the number of interceptors that the Allies have bombers, so you might see 55 German FB-F's intercept this AD, and get bounced by your 360 P-47's. Possibly gamey move. Again, you need to recon the target, or the bombing mission may not fly.
Set the other AD to bomb the same UB targets around Hamburg, assign 8 of your best EXP B-17 groups and all four P-36 groups. Set schedule to 2/4/7, altitude at least 21K', req AC 75/50.
Coastal Command - If you're playing 1943 campaign, it's not important to fly them now. You can leave them all on None mission, in which case they may fly and crash anyway, or set them all to Rest until you get closer to invasion dates. I typically set up size 4 Naval Patrol AD's over four parts of the channel from Belgium on the East to off the Channel Islands on the West, assign four groups to each, and rest two of them in the Allied turn and the other two in the Axis turn. Hopefully it builds up experience but I will tell you I have an EXP 62 Norwegian group that hasn't improved in 22 turns. The Fighter Command AS AD's should protect them. Swap out the Sutherlands for Venturas. That will increase the group size from 9 to 12 planes, and the Sutherlands have a max altitude of 16K'. I like to fly my NP AD's at 21K' or more, given the German FB-F's are less effective at that altitude.
In the South:
Again, if you're playing the 1943 campaign:
Recon - Do size 3 Interdict target-type recon over and behind the invasion beaches, so for example hexes 150,293 and 143,290. Schedule 1/2/3/4/5/6/7, strike number 8, req AC is 3.
Ground Attack - Set size 3 Interdict Ground Attack AD's over the same hexes as the recon. Fly days 2/4/7 (if you fly every day, your air groups' morale will go into the teens and you'll need to rest them for 1-2 turns before they're healthy again). Assign the FB's to these missions, as they get much higher interdict results than do the medium bombers. Set altitude based on the flak you can see in the area (shift-o twice), but remember that the FB's will do dive-bombing from 11K' over the target, so they will suffer more than do the LB's. You also can fly the B-26's in the same role.
Fly one Railway Ground Attack AD with a size-2 area over 160,280 with all the Wellingtons and the Spitfires (out of Victoria). Set the S Base (Staging base) to Victoria so the fighters have the longest range. Make sure they have 90gal tanks. Fly this AD 2/4/7 days at 11K'. The idea is to use this AD to draw lots of German FB's. You should be able to assign 496 bombers and 240 escorts, but set Strike number to 10 and Req AC to 49/120. The AI usually assigns its interceptors to the first few strikes, and your 240 escorts will be assigned to the first two, so they should overwhelm the interceptors and your other strikes will have little or no interception. Possibly gamey move.
Air Superiority - The Axis will do a lot of interceptions around Pantalleria the first turn, so assign your P-40N FB-F groups to a size 5 area at 136,296, 1/2/3/4/5/6/7, Both air phases (the German fly both), altitude 24K'. You shouldn't need drop tanks, so take them off for better performance.
Strategic Air Force - the first turn or two I use them to do Railway strikes on the toe of Italy. Fly days 2/4/7. But also start preparing Derna, Tolemaide, and Benghazi air bases in Libya so you can bomb the Ploesti area fuel and oil targets from there. On those bases, set Max TOE to 100, Supply Priority to 4. If you're playing against the AI, after turn 3 or 4, move your Strategic Air Force LB's to Derna and Tolemaide, and the F-9 recons to Benghazi, and start recon-ing and bombing those Ploesti targets. If you're playing a human, this may not work, as humans often keep lots of FB-F air groups there for this very reason.
Coastal Air Force - fly three size 3 Naval Patrols with enough groups for about 40 AC each off the invasion beaches at the SE tip of Sicily. Rest half the groups in the Allied turn, half in the Axis. Spread the rest of your PA and TB air groups across the North African coast from Oran to Philippeville and Victoria, to keep those sea lanes open for ground supply.
1. Luftwaffe FB's are the objective - You should be killing as many German FB's as you can every turn, both to save your LB losses and to make your AD's more effective. To do that, allocate both your Strategic and Ground Day bombing AD's to fly 1/3/5, 2/4/6, and 3/5/7. The Allied groups assigned will only fly three days a week, but the Germans will have to fly seven days a week or let the day 6 and 7 AD's go uncontested. Fly Strategic missions where you over-allocate escorts compared to bombers, then use the Req AC settings to make sure all those escorts go out on missions (see "8th Air Force" above).
2. Staging bases - always check the Staging Base the game sets, and change it so maximize your escorts range (i.e., set the staging base to the escorts' base rather than the bombers' base).
3. Rest - rest all air groups assigned to Ground Support during the Air phase, then set them to Day/Night before you start the ground phase. They will recover some morale during the air phase.
4. Morale - rest all air groups with morale of 50 or less, and most air groups of morale of 51-55 unless you need them REALLY BADLY and they have higher EXP (i.e., 75 or higher).
5. Ground Attack and Ground Support assignments - assign your high morale air groups to Ground Attack missions and your low morale air groups to Ground Support. As mentioned above, if you rest the Ground Support ones, they will recover some morale and may be high enough the be effective during the Ground phase.
6. 500lb v. 1000lb bombs - Others disagree, but my experience and testing are that 2x1000lb bombs are more effective than 4x500lb bombs. Rockets don't do much for me. So I use 1000lb bombs whenever I can, for both Strategic and Tactical bombing.
7. FHEX (Friendly Hex) Interdiction - as the Allies you're almost always advancing, so interdicting your own hexes is a waste of bombs. Make sure this is set to NO. And when doing an Interdict AD, count the number of Enemy-controlled hexes within the area, then set the Strike Number to that number of hexes and set the Req AC to the corresponding fraction of assigned planes. For example, if you have 227 bombers assigned to an interdict mission over 5 enemy hexes, set Req AC to 45.
8. Northern Europe invasion prep - for 4-5 turns before your planned Normandy (or other target) invasion, use ALL your LB's (heavies and mediums) to attack Railways and Railyards from Normandy to Holland. Alternate the two targets by turn. DON'T use your FB's for this, as you want to save them for the invasion turn. Here's my targeting plan:
Air Command AD Type Target Area Railyard Targets
Bomber Command Ground Attack 98,193 4 3
2nd Tactical Ground Attack 89,186 4 9
8th AF Ground Attack 105,176 4 14
8th AF Ground Attack 113,179 3 14
8th AF Ground Attack 104,184 3 4
9th AF Ground Attack 90,198 1 4
9th AF Ground Attack 98,184 4 11
9th AF Ground Attack 82,196 4 5
9th AF Ground Attack 86,207 5 6
Then on the turn before your invasion, move all your ground attack missions to Interdict the area at and immediately behind the invasion beaches (2-3 hexes deep). Do the same the turn you actually launch your invasion. You should have interdiction levels of 5 or higher, which is death to moving German units.
I hope this was helpful. Let me know if you have more questions.
Very interesting, thanks