Inspiration from Artists Week 52 Bonus Artist Edmund George Warren. Changed to Charles James Adams .

Duplicated 

I always use watercolour and used to be quite anxious about not spoiling a painting, which means you tend not to take risks and can end up painting a bit too tentatively. I’ve found there are a number ways of correcting a painting that you might think is only fit for the bin.  As Alan says, using a robust paper helps enormously (I use 300lb Saunders Waterford) as you can scrub or lift out areas without damaging the paper.  I did try the watercolour magic sponge eraser, which does work but can also remove more of the surrounding area than you’d like and is a bit messy.  My preferred way now of correcting either very small or even large areas is to coat what you want to change in a layer of gesso.  (I use Liquitex Professional). The painting below on the left was completely reworked this way - the reworked version is on the right. Another way to save a painting which you can’t take any further is to use a soluble wax pastel on top, either dry or wet - I’ve saved quite a few this way.  If you think a painting is ruined anyway, you can be more adventurous reworking it and often come up with some surprising results!

There are two cheaper papers for watercolour that I find forgiving of error, and can be washed out successfully if you make a mistake: one is Bockingford, the other The Langton (which might indeed BE Bockingford, now I take a closer look).  I wouldn't use anything cheaper or lighter than that: that's a great way to get disappointed with yourself, and think watercolour isn't for you. Papers like Arches, Saunders Waterford, Milton (or is it Milford?  Haven't got any at the moment), Hahnemuehle, Schoellershammer, the heavier weights of Fabriano (I really HATE their lightweight paper), are lovely to paint on IF you choose one that suits your style - it's important to do so, because some papers just won't, however good they are for artists who can work with them.  Eg - I do like Bockingford rough, but recently have found I get on better with NOT surface, or even hot-pressed, in the heavier weight cotton rag papers.   And yes, it does get expensive - but then, what doesn't?  Necessary sometimes to just bite the bullet, buy the paper and paint, and set the dog on the bailiffs (I don't really recommend that, but how anyone can pursue a career as a bailiff I just don't know; there is, and this gives me some hope for humanity, a very high drop out rate: I enjoyed one explanation: "I couldn't live with being a complete bastard all day and every day" - well, well done you.  I digress, as so often....).