Andrew Whitson The watercolour paints he uses for his illustration work.

Always use the best you can afford.

I have found through a lot of experimentation over the years that  it is always better to use the absolute best materials that you can afford when it comes to rendering final artworks.
Obviously what works for one person may not always work for someone else, so here are a few photos and some notes to illustrate what I have found works for me.

 I have been using the Daler Rowney Artists quality watercolour tubes for a number of years namely because of their rich colour characteristics.

It is essential though to use these sparingly due to the richness of the pigment in these tubes.

My general process ( which I will discuss in another article) uses .5mm technical drawing pencils with an HB lead which is quite hard but leaves a lighter line when transposing an image onto the often expensive paper.

 I have found the best brushes for painting in watercolour have always been sable 

 as opposed to artificial brushes. These are invaluable, especially when applying large washes as the sable hairs have the ability to absorb great quantities of colour that can be fully applied to the paper.