making a collage.

we were learning to make a digital collage. A collage is a collection of shapes with lots of texture usally those shapes are already made and usally you overlap them a bit.
I think there are two types of collages you can make one is deatailed and it will take longer and look a bit better the other will take very short and will still look prety good. what are your tips for making a collage better and make it take shorter.