Hi Jodie, all my miniatures were painted with a tiny paint brush and expensive artist watercolours -the ones used here cost £39 99p for 18 half pans. You can shop them cheaper on Ebay now.
Yes, I have noticed the quality - very strong pigment and when you do paint washes you need to do more clean water washes to remove excess layers.
I am experimenting with different textured paper at the moment, just learning about the potential with each, there is hot pressed type - smooth surface and cold pressed called NOT rough to very rough surface. I have even looked at some big sheets that cost £4 + French make I think and these contained some cloth material in the mix so I have been told.
Maybe you could try some poster paint on the very rough watercolour paper that will give you some kind of a textured surface. I would use the 300grams weight ones cos you can actually cut/scratch a tiny bit off the surface if you make a mistake.
Finally, you need patience with each piece of art. I have been distracted so much lately, I am finding it hard to go back to oil paintings that I have started previously.
Lily