From: Honolulu, Hawaii
It depends on how much level of detail you want. When I create a map I do not like the map to be cluttered. I tend to only place major cities, roads, ports, airfields, and rail lines. Of course, I try to get the topography as correct as possible. I find that the Perry-Castaneda Library Map Collection to be an excellent resource for map making.
I start with the outline of the map and then place terrain, roads, cities and features. Sometimes maps take hours to make, sometimes days or even weeks depending on how much time I put into it and the size of the map.
Are you creating a full map of both countries or just the border region?
*Warning: Dr. Foo is not an actual doctor.
Do not accept or follow any medical advice*