A few more Tips when watercolour
Always have at least four containers of it near your work. At any time, one will be available and clean so that you can mix colours cleanly, clean brushes in another, and rinse in the others.
Colour testing is always a good idea, rather than charging onto the surface of a painting with an untried colour. Test on a small sample of the same surface on which you are working. Make notes and file the samples--great future reference material.
Mixing quantities of paint for large works can be done in lidded containers rather than on your palette . This means less remixing time. Colours can be used for future projects, so waste is less an issue than efficiency.
Papers are varied and offer many surface qualities. But, occasionally, bends, folds and accidental creases occur. This damage can happen before the painting is done or after it is completed. To remove it, press lightly from the back side with an iron. Be sure to use a clean paper under the painting while pressing.
Flatten buckled paper with weight. Allow the painting to dry completely and then place it between blotting papers with weight evenly distributed over it. Often it is possible to stretch the paper after the work is finished. Do this by carefully dampening the back side of the paper, then gently stretching.
Create soft glazes over completed dry works by spraying the surface with diluted paint in a plant sprayer. This will dry to a soft, cloud-like appearance. Some experimentation is needed to get the right mix of water and surface absorbency.