How to model a realistic boulder?

[purplemonkeydishwasher]

I'm trying to make a boulder with applying a lambert shader and using a spherical projection of a rock texture onto the the boulder (which is a deformed sphere) but it just looks rubbish. Can anyone advise how they would go about modelling and texturing a boulder for photorealism?

[joojaa]

Err... why exactly would the boulder look good this way? I mean explain a bit more what you want i mean its like saying i drew a cat and it looks like a dog please help, without supplying a picture.

Sorry cant be helped. However I'm more curious why did you expect it to work? THsi would give me insight on the problem.