Choose your pumpkin. A good pumpkin for painting has a smooth, even surface with no bruises, scratches, or blemishes. Pumpkins with light or very light or shallow ribbing will have the smoothest surfaces. Avoid pumpkins with too many lumps and bumps, or they will be difficult to paint. Look out for any cuts or wormholes that will cause problems, and make sure that the pumpkin is flat enough to sit upright.
Watch out for any soft spots in the pumpkin because that may be a sign of rot. You want your pumpkin to be fresh and to last as long as possible.
Almost any variety of pumpkin can be painted, but the following are especially good: Baby Pam, Sugar Pie, Neon, Lumina, or Cotton Candy.2
Choose a design. Before you start painting, you should have your heart set on a design. Almost any design can look good on a pumpkin, as long as it's not too complicated. Faces are popular, but you could also choose a black cat, bats, a haunted house, geometric shapes, or anything you like.
Paint your entire pumpkin with a solid color (optional). You can use the natural color of your pumpkin as the background for your design, or you can paint the entire pumpkin another color. Use an acrylic paint to paint the pumpkin. If you have other paint at home but aren't sure if it'll work on the pumpkin, test it out on a small part of the pumpkin to see if it sticks first.
Pick a color that complements your design. If you're drawing a goblin, pick an eerie green color for your background.
Paint your pumpkin in sections, allowing each to dry before moving on to the next. This way, you won't be stuck holding a pumpkin dripping with wet paint.
Watch out for the wet paint on the bottom. Make sure you don't set the pumpkin down on its bottom when the bottom is wet, or it will stick.