Spackle Everything At Once
Approach the spackling portion of your project in stages. Find all the holes, cracks and dings in your wall that need repair. Spackle everything at the same time. If you do it this way, then sanding and additional applications can be applied at the same time, as well. This may seem more time consuming initially, but in the end it will help you stay organized and finish the job without having to deal with constant touch-ups.
Spackle Twice, Sand Twice
After the first coat of spackle is applied you have to lightly sand the finish before taking any further steps. Don't touch the spackled wall until the spackle has dried completely. Consult the specific brand of spackle paste for approximate drying times. If you attempt to sand the wall before it dries it will ruin the application of spackle by rubbing it off. Wear a dust mask prior to sanding. Using a sanding sponge or sanding block, lightly sand the spackled area with a medium grit sand paper followed by a fine-grit sandpaper for a smooth finish. Do not over-sand or else you run the risk of sanding off all the spackle. Apply a second coat of spackle and repeat the sanding process again. This time be extra careful to sand evenly to avoid creating sanding grooves from your fingers.
You should always prime your walls before painting them. Priming covers the old surface and allows you to apply fresh colored paint evenly without any remnants of your last painting project showing through. This is especially significant when you spackle. The spot you just spent a few hours repairing may otherwise show through new paint if the wall is not primed, especially if the white spackle repair is not the same color as the old paint job. Primer is a base coat of paint. it is most commonly used as a simple white, but can be tinted as well. Tinted primers are used if you plan on applying a deep base color to your walls.
Once the priming is complete, you're ready to apply the first coat of new paint to the walls. Once the primer is dry, inspect the walls for drip marks or uneven strokes. Use a medium-grit sanding block to smooth out any rough or uneven surfaces form the primer application. Start by painting the edges of the walls with a paint brush, followed by using a paint roller to apply your coat of new paint evenly to the rest of the wall's surface.