If I'm not mistaken, layering and thinning can be done to every part of your hair (e.g. back, fringe, sides...). It all depends on the cut and the style you're trying to achieve.

Layering
- literally means putting layers into your hair
- to add texture to your hair

Thinning
- your hair is cut, but the length is still somewhat kept (meaning won't cut until too short)
- usually to make your hair lighter, so that it's easier to be styled using styling products (e.g. wax, clay)
- there is a type of 'thinning scissors' which can be used to achieve this

As for spiking your hair (e.g. the top), just let the hairstylist know that you wanna spike your hair, he/she would know what to do

All the best

p/s: Please correct me if I'm wrong, I don't wanna go around spitting the wrong info lol

Where can I get this Joico erratic molding clay? Do you know if it can be found in places like 1U, Curve, Mid Valley Megamall?

Thanks in advance