Solid wood is an amazing material because it can be cut, re-shaped, extended, filled, sanded, stained, painted, and essentially re-used almost endlessly.
Last week, I took old cabinet doors (from when we gutted the mouse-hole kitchen cabinets that used to be in our apartment before we moved in) and turn them into a free cubby for my daughter's closet. :)
Small paint brush for cut-ins, foam roller for surface coverage. Allow recommended dry time between re-coats.