1. Winsor & Newton Cotman Watercolour Tubes
I've tried many different watercolour sets, but have found using these tubes the best, and most cost effective. You only need a really small amount (about the size of a pea) of each colour on a paint palette, and even if the paint dries, it can be softened with water to be used at another time. I'd guess an 8ml tube lasts roughly a year for me.
I've also found colour mixing much easier with tubes as opposed to pans, as you're not mixing directly onto a pan so you can see the colour clearly.
I'm not saying this range is the best you can get, but if you're on a tight budget (as I am) these will fulfil your needs. That being said, the pigments used are cheaper alternatives to the rest of Winsor & Newton's range, so if you're creating an extra special painting, or if you have more money in the pot, I think I'd explore other options as well!
2. Pro Art Prolene Plus Brushes
These are cheapish (of course!) but slightly more expensive than what I was using before. As a result, they hold paint well and keep their shape. Another plus is that the varnish doesn't crack off the handles onto my hands and subsequently get wiped all over my face. (This used to happen. A lot.)
3. Langton Watercolour Paper 140lb /300 gsm NOT cold pressed
Again, this isn't the cheapest option for paper, but it's the cheapest I would go, if you want quality paper. I think its a good weight for me as I apply paint quite thickly and without much water. I'm not quite sure how this paper would fair with heavier, water soaked washes, but for smaller, illustration-style paintings it's ideal, and detail doesn't get swamped in texture. I get an A3 pad and an A4 pad - and I would avoid ring bound books.
4. Winsor & Newton Designers Gouache Gold 30ml
I've recently started adding this to my paintings, it's a really clean gold colour, not yellowy or brown like some gold paint. It has a lovely metallic quality without being too thick and so contrasts nicely with watercolour.
Do you have any materials to recommend to fellow artists? Anything you can't be without?
Please share below!