So back in October I filled my wheelbarrow with a pumpkin or two and a slew of gourds for painting. Gourds may be spherical, peanut-shaped, pointy, etc. I try to choose a variety of shapes and sizes. Pick up a gourd and look at it. Does its shape suggest anything? A snowman, Santa, elf? Maybe a jack-o-lantern, a piece of fruit, or a bird.
Make sure the gourd is sound - no cracks or holes. I've been told that generally a gourd with lots of seeds inside has thicker, stronger walls. If it's going to need to stand up, make sure that it does. (You may want to make some hanging ones, too. The crook-necked ones are great for that.) Sometimes a wobbler can be sanded a bit on the bottom to stand better. Sometimes you just need to shake it and move the seeds inside to make it stand up.
Step 1: Clean the gourds
Once I get them home, I brush them off, then sand with 150 grit, or whatever sandpaper I have on hand. Then I give them a good rubdown to remove loose dirt and sanding residue.