I've come across two types of GPS approaches in my limited experience so far. There are GPS overlays for existing approches (NDB, VOR,....). Then there are stand alone GPS approaches, which only require a certified GPS reciever. These come in the same "T" shape. An 5nm intermediate section to the IAF 90Deg to the final approach track. The final approach segment consists of two 5nm legs, IAF-FAF and FAF to MAPt. They are very easy to fly since you don't have procedure turns or timing worry about. They are all the same shape. The neatest thing is that a few decent GPS units (e.g. Garmin 430) will even tell you when to turn to intercept the final approch track. You don't have to think too much about wind correction since your magnetic TRK is displayed on the GPS reciever.
In short any muppet who can hold ALT/HDG/SPD in IMC (just like me
) can fly a perfect GPS approach.