a 3d effect?

Does anyone know how to build up acrylic paints to achieve some sort of 3d, textured effect?
Is there a product that can do that or do you just have to layer the paint?
I probably sound really dumb, I'm struggling with an idea that I cant figure out how to start.

 

anyone know?

 

just glob it on really thick?? i've recently tried this, it takes a lot of paint

 

thanks.

 

Sand .... added to the paint.

Also there are textured mediums that are for sale in some art stores, that are meant to be added to paint.

You could also try: unscented kitty litter - instant coffee granules

 

You might try painting knives, which give more texture.