Put down newspapers or a tarp in a well-ventilated area.
Put your furniture piece on top of the tarp and sand its surface, whether new or a garage-sale find, to prepare it for paint. Wipe down with a tack cloth.
Apply primer with a brush, ensuring you cover the entire piece. Let it dry, according to manufacturer instructions.
Brush on a coat of flat paint in your chosen color, a lighter shade is best for this project. Work the paint into any carved areas or crevices. Let the paint dry thouroughly.
Gently sand areas of the piece that would naturally become worn over the years. On a chair this might include the edge of the seat front and the back where you would naturally grasp it to pull it in and out from a table. On a table, the edges of the table top and bottoms of the legs would show wear; a dresser might be worn around the edges of its top as well as around any pulls. In some areas allow the primer to show through, in others go all the way to bare wood, whatever looks most natural to you. Dust with a tack cloth.
Apply the aging glaze with a brush, coating the entire piece.
Wipe some glaze off the raised edges of any carved details or spindles with a slightly damp cotton cloth to provide more depth and the look of years of handling.
Allow the piece to dry when you are happy with its look, then top coat the piece with a polyurethane finish.