I had a fun project that I did a little while ago. I made a jewelry box for my wife. I bought some wood PLA. After a little bit of testing, I decided that I wanted it to have that wood grain look and so I did some research into finding out how to do that. I found a script on Thingiverse that varies the hotend temperature within a range while it is extruding. This had the effect of turning the filament darker at higher temps and lighter at lower temps, giving my jewelry box a woodgrain appearance. Give it a try if you have any wood projects coming up.
Wood Grain