Whether you're painting a canvas or a wall, glitter can make your surface literally sparkle. Several companies make glitter paints, but when they do not offer the right colours, or use too much or two little glitter for your needs, you can easily add some glitter to paint on your own. The only trick is to buy the right glitter for your paint.
Purchase the right glitter for your paint. For watercolour paint, use craft glitter (available at any arts store). For any other type of paint though, purchase graphite glitter (available from both art and hardware stores). In anything but watercolour paint, craft glitter will be too small to notice.
Pour a little paint into a paint tray -- a disposable pie pan will work in a pinch. Testing out a small sample first helps you avoid over-glittering all your paint.
Add glitter, a little at a time. Mix thoroughly as you go.
Periodically test the paint on a surface similar to the one you will be painting on. When you have the right glitter consistency, stop.
Pour more paint into the paint tray. If you can -- for instance if you're painting a piece of paper in a single sitting -- pour as much paint as you think you will use. If this is impossible -- for instance if you are painting a wall -- just pour out enough to last you this session.
Add glitter until it achieves the same balance as your test sample. Stir throughout.
Paint your surface. The important thing to keep in mind with glitter paint is to be stirring constantly. Glitter, particularly graphite glitter, will sink over time. If you do not stir every time you dip your brush, you will lose the mixture's even consistency.