From: Sydney, Australia
+1 to keeping the interception numbers as high as possible, I set it to 300 throughout the game. Evenutally your numbers will win out -- I'm routinely seeing 40-50 German fighters and bombers turn up to find my stack covered by 300+ fighters, and a lot of those bombers don't go home.
Apart from VVS (bombers and transports on these bases set to night missions will supply partisans), the base designations don't actually mean anything. Always keep a good mix of fighters and bombers on each base.
Make sure you rotate your planes to the reserve very often. At the start of each turn I pick up all of the low morale units and fly them back to reserve. At the start it doesn't matter if the units you're replacing them with aren't much higher in morale, but the morale will build up over time (simply flying a unit back to reserve bumps its morale up, so the more you rotate units the more the morale will go up). Experience is what really matters but that won't grow higher than morale so focus on getting the morale up.
I never disband SAD bases. Every AP spend disbanding the bases is an AP I can spend somewhere else.
By about mid to late 42 I'm disbanding low morale air units especially those with older planes (I15s, I16s, Su2s, SB2s) rather than flying them back to reserve. There's some kind of hard limit on the number of air units you can have, better to put the pilots back into the pool and let the units of the more modern planes build up.