learn to paint

I'm experimenting with paints. I've found that Golden heavy body paints are thick and useful for texture.

But, liquitex soft body paints feel practically like ink in that I can easily draw lines using a liner brush.

Just adding water to the thick paint doesn't achieve the same thing. Is there some sort of material I can add to thick paint to achieve the same effect so I don't need to stock up on multiple types of every color?

I have found that painting fluffy white clouds or shadows or gradients is highly dependent on brush type, type of paint, how dry the paint on the brush is, how dry the paint on the canvas is, etc.

I am trying to figure out how to do this consistently. Is there a type of paint best for this? Maybe one that is chalkier somehow compared to most paints that are heavy bodied?