Basic tools and materials for your unfinished cabinet painting project include sandpaper (both medium and fine grit), a flathead and a phillips head screwdriver, a drop cloth, a paint stir stick, a damp cloth or sponge and masking tape, as well as both small (1 inch) and medium (2 to 3 inch) paint brushes.
Decide whether to paint or stain the cabinets. If your cabinets will be installed in the kitchen or bathroom, gloss paint is easy to clean and offers the option of adding color to the room. Stain brings out the natural beauty of the wood, but color options are limited to muted tones, adding depth rather than brightness to the space. The wood fibers of stained furniture remain exposed to moisture, giving bacteria a place to hide and making cleaning more of a challenge. The easiest products to work with are water-based. If you choose an oil-based stain, add mineral spirits or turpentine to your materials list for clean up.
The easiest way to do a professional job painting your unfinished cabinets is to paint before the cabinets are installed. This way you can set the cabinets in one place on a drop cloth and have clear access to all sides and the insides of the cabinets. It also simplifies things and creates a better finished product if the doors of the cabinet are removed and painted separately. Most unfinished furniture has not been fully sanded. Use the medium-grade sandpaper to smooth rough spots that will take paint or stain in clumps and disrupt a smooth final appearance. Once all the surfaces are consistent, use the fine-grade sandpaper to give an additional finished shine to the bare wood. The better the wood looks before you paint, the better your final product will look.
Before starting to paint, use masking tape to protect edges of inside shelves. Use smaller brushes to paint panel edges and edge inside walls. Use arger brushes for the larger surfaces, using broad strokes to apply sections of paint at a consistent saturation. Once you have fully covered all the surfaces, let the whole project dry, preferably overnight, before applying a second coat. If using stain, let the product saturate the wood, and wipe down all the surfaces to remove excess stain. Most unfinished furniture will cover nicely in two coats, but decide yourself when the cabinet looks finished.
Clean up for water-based brushes is easy with soap and water. Oil-based products will require some soaking in mineral spirits followed by soap and water wash. Clean small spills right away to avoid leaving traces of the project behind.