I've got a habit

[Alien]

try to use milestones
1. night - layout with basic combination of textures
2. night - detailing 1/4 part of map
3. night - detailing 2/4 part of map with details
4. night - detailing 3/4 part of map with details
5. night - detailing 4/4 part and publishing
(so max 5 nights)
I often did map in one night, more days means only messing what is done already :P Then i published, players left or stayed so then i add some improvements.