You can use them at the same time by using different Blend modes
and opacity
levels.
Good thing to remember is that they stack up in order kinda like if you had layers:
- Color Overlay - ( Above
Gradient Overlay
. )
- Gradient Overlay ( Above
Pattern Overlay
. )
- Pattern Overlay ( Below both. )
..and no, you cant change the order. What you can do is use different blend modes and opacity levels as mentioned and you will pretty much be able to do the same thing no matter what order they would be in.

Also, in the layers panel if you open up the Effects ( or FX ) and right click one of them and select Create Layers
, you can then control the position of those former layer styles, difference being that you cant control them like you could from blending options
because they are layers. You can however put Layer styles
in them if you want to.
