Let's talk a bit about hair types.  We get so focused on the curl that sometimes we forget that it's HAIR that's curling.  Hair has a few things going on...

Density - This refers to the number of hairs per square inch. Typically, the darker your hair, the higher your density.  If you have a higher density, you actually have MORE hairs.  That means you will need more product.  If you're a blond, you will probably need less. 

Porosity - If your hair is very absorbent, you will need more product and may benefit from things that add protien to the hair.  Chemically damaged hair is often very porus.  On the other end of the spectum, if your hair takes a long time to get wet and/or doesn't soak up a lot of product, then you might want to avoid protien containing products. 

Texture - Are you individual hairs so thin you can barely see them or are they so thick that they look like small wires?  Most of us are somewhere in between but there is definitely a texture.  Fine hair needs to avoid heavy products to keep from being weighted down.  Coarser hair may need heavy products to help control shrinkage during drying.