Scale of Levels
Something that is always a challenge in an early project is the scale of levels. Without gameplay to verify what you are doing it can be very hard to get a good sense for the level. As I have been stumbling on this a couple of times now I have divided how to go around the scale of a level in three methods:
Hatching Method
When using this method, you start out building on many different places all over the estimated map size and try to fill out the whole level at once. This was how I started creating the levels and it proved to be ineffective and clumsy. The two biggest problems with this method are: (1) that it tends to have no coherency between the scenes in the level and (2) it creates a lot of gameplay void (i.e empty spaces.)
Mass Expand Method
The first thing you do if you use this method is picking a couple of different places in the level and build scenes separate from eachother and expand them to the point where you can connect them to the surrounding scenes. This method proved to work a lot better than the Hatching Method, especially on the Farmland level in which each farm was a self-contained gameplay area.
Single Expand Method
Using this method you will pick one point on the map and expand from it until a plausible map size is found. Building levels this way proved to give the best coherency and is now the method I prefer, though for some maps the Mass Expand Methods might still be more suitable.