Choose a good palette knife before you start painting. Palette knives differ in quality. Look for a palette knife that offers some flexibility in the blade and has a comfortable handle.
Pick up paint with your palette knife by sliding the knife across your paint. It's very similar to using a butter knife to scrape up butter to use on a piece of toast.
Hold you knife in whatever way feels most comfortable for you. To add paint to a canvas, "butter" the canvas with your knife. You can also make small dots by using the tip of the knife and fine lines by pressing down with the edge.
Enhance the texture of your painting with the palette knife. Load your palette knife with a lot of paint and apply wet paint to wet paint on the canvas. Sweep the knife across your canvas, like you would when buttering toast. By lifting the knife as you swipe, you can create ridges in the paint.
Add layers of color with your palette knife. Layer the lighter colors on top of the darker colors, using a moderate amount of paint on your palette knife. With a palette knife, you can layer colors on top of each other without damaging the layers underneath.
Scrape the paint on your canvas with your palette knife. You can use this technique to erase mistakes or to add texture or detail. Use the blade to scrape larger areas and the tip for smaller areas.
Clean your palette knife when you finish painting for the day. Just wipe the paint off with a cloth, making sure that you wipe until no more paint remains and you have a dry knife.