1. Allow yourself plenty of time. Furniture stenciling can be very labor intensive because there are so many steps and layers involved. Also, since it is a three-dimensional object you will oftentimes have to paint details in and around awkward and carved areas. And finally, allow each primer, base, and finish coat to dry thoroughly between applications.
2. Do it right, do it once! Take care to do each layer of primer, basecoat, painting, antiquing, and finish coat right. You don't want to have regrets about brush marks your should have sanded down when you end up with a fabulously painted piece.
3. Look for cheap antiques to paint. When learning how to stencil, scour yard sales, thrift stores, and Granny's garage for inexpensive furniture with interesting lines such as turned legs and carved detailing. Lesser quality woods and slightly damaged veneered surfaces are crying out for a painted and stenciled treatment. Create interest on a plainer piece of furniture with some embossed stenciling and panel effects.
4. Don't strip unless you have to. There are many good bonding primers on the market, such as Kilz and Aquabond, that allow you to simply sand, clean, and prime over previously finished surfaces, without stripping. Waxed finishes are the exception, you must strip, so avoid them and go for previously painted or worn finishes.
5. Turn new furniture into instant antiques with distressing. Before beginning painting, take out your aggressions by hitting the edges of the furniture that would naturally receive the most wear with a small rock. Add a small amount of wormholes with a hammer and awl. After painting you can distress the edges by rubbing lightly over them with fine grit sandpaper. Be selective with your distressing so that it doesn't become overdone and fake looking.
6. Work with a limited palette. You can gracefully combine different patterns by sticking to a limited palette of 2-4 different colors. Also, when combining patterns, think of variety of scale. Just as when working with fabrics, choose a large-scale pattern to combine with a small print. Add in some stripes and checks and you will have an interesting, coordinated piece.
7. Create a soft, mellow, aged look and unify colors and designs by antiquing your furniture. I prefer to use an oil-based gel stain in a soft dark brown such as Walnut (Minwax stain is good), for the best look and easiest application. When finished painting, apply one coat of water-based varnish to seal the surfaced and protect your painting. Apply gel stain with a foam brush and wipe off excess with cheesecloth. Allow the stain to dry 2 days and finish off with two more coats of water-based varnish (Minwax's Diamond Varathane finish is compatible). If you prefer not to use oil-based stain, substitute water-based stain or glaze instead.
8. Protect your art for the ages. Furniture will receive a lot of wear and tear. Protect your time and creative investment with a minimum of 3 coats of water-based varnish (oil will yellow, so avoid it especially on white and light colored backgrounds) in a satin finish
9. Be bold. Learning how to stencil and painting furniture is not like painting walls, which completely surround you and generally are kept neutral and comfortable. Stenciled furniture can become an accent piece in a room, adding some punch and pizzazz. See how many different stencil designs you can put on one piece of furniture. OK, this tip is kind of self-serving, but try it and see how much fun it is!
10. Embellish! If you are creating a really fun, whimsical piece try incorporating upholstery trims, tacks, beads, and tassels into your furniture piece. Other ideas include buttons, lace, fringe, mosaic, and decoupage. What else can you think of?