Wash. To begin, I usually just wipe down a piece to remove any dust or dirt. I personally have never used a primer with chalk-type paint, but I would suggest it if the piece has a really glossy finish.
Paint, at least 2 coats. Paint the entire piece with paint. I usually use a brush (but a small roller could come in hand for some pieces such as cabinets). You'll find that a little paint goes a long way, and I almost always use two coats of paint. Chalk-type paint dries really fast, but make sure the first coat is dry before applying the second.
Clear Wax, then Dark, if desired. After the paint is completely dry, apply two coats of wax on the piece using a wax brush. I don't wait for the first coat of wax to dry before I apply the second coat. A tip when waxing, less is more!
Dark Wax is optional. Use it if you want to bring out details and/or like the aged look. You must apply clear wax BEFORE you apply dark wax. Go easy on the dark wax. You won't need much! Apply the dark wax with a brush over somewhat dry clear wax.
Remove excess wax with a lint-free cloth.
You are not limited to using wax,. For high-use, high-touch pieces such as kitchen cabinets, table tops, desk tops, floors, and outdoor furniture, I would recommend a water-based polyurethane protective finish such as Polycrylic.
Buff. Buff the wax using a lint-free cloth. It's pretty easy to see where you missed the wax, so you can easily touch those places up with a brush or rubbing wax in with your cloth. Buffing helps smooth out and remove extra wax.
Sand. If desired, sand to give the piece an aged, worn, imperfect look. I recommend sanding after you apply the wax because of the chalk nature of chalk-type paint. It will make a mess if you sand before waxing and then you risk mixing the paint particles into the wax. I usually sand the edges and places where normal wear and tear would occur.