I have a 32' x 48' shop. Went that route as someone else has already mentioned, so there's not a lot of lumber wasted. I went one block high off the slab and used full 8' 2 x 6's for my walls. That gave me 9' ceilings. I have an 9 x 8 overhead door on one side and a set of double doors on the other(located on the gable ends so as not having to deal with rain or snow coming off the roof), plus a couple of entry doors at various locations around the building. I have it partitioned down the middle lengthways and only heat 1/2. The heated side is 1/2 wood shop and 1/2 general purpose, it has a bath with a shower and a 3-partition stainless sink. The heated side is also drywalled and painted giving me flexibility should I want to license it for processing chickens, etc. I installed 100 amp service to the building. Down the center partition wall on both sides I located 220 plugs 8' OC and 110 plugs at about 6' OC in the partition wall and around the perimeter of the building. I have a mechanical room at one end where I house the hot water heater, boiler and well mate. Next to that is the bathroom, so I keep all my water requirements close together. I have 3 zones off the boiler, one for the GP room and bath, one for the woodshop, and one for future expansion. It works out pretty nice.
A shop should be planned around ones current interests and any that one may have in the forseeable future. Care should be taken in laying out outlets and overhead lighting.
Basically what I ended up with is a great shop and (because of the strategic location of windows) an extremely large deer blind.