We’ve already covered one of the cardinal rules for painting: Always save your original paint, because you will probably need it for touch-ups.

When patching dings and nicks in the wall, here are some basic guidelines to getting a beautiful finish that won’t give it that
“I-patched-up-my-walls-now-can-you-tell” look:

1) Use a small amount of patching compound on a small patching blade, keeping the blade very close to the wall.
2) After it dries (…may take up to 24 hours or so depending on how deep and wide the nick is), sand the patch wall with a fine sanding block (with 180 or more grit), using long and light strokes.
3) You may need to put another coat of patching compound, since patching compound shrinks slightly after drying. Let dry, then resand.
4) Prime the patched spots with a water-based primer. Make sure you rinse your paint brush clean afterwards!
5) Paint the patched and primed area with the original paint if possible. Depending on the color and quality of the paint, you may need to use 2-4 coats, allowing each one to dry completely.