Sand the bark off the sticks so that they're smooth. Inscribe each of the sticks with one of the Ogham symbols. You can do this either by carving them into the woods, painting them on, or using a woodburning tool. The ones in the photos were made with a woodburning tool, which cost about $4 at a craft store.
Consecrate your staves as you would a Tarot deck or other magical tool.
There are a number of methods to reading the staves for divination, and you can figure out what works best for you. Many people like to simply keep their staves in a pouch, and when a question comes up that needs to be answered, they place their hand in the bag and pull out a designated number of staves. Three is a good number to use, but you can pick as many or as few as you like. As you pull each stave out of the bag, use the information at the Ogham symbol gallery to determine its divinatory meaning.