I shaped a log from our firewood pile into a slab, and drilled holes for the tea lights. Its pretty simple really- but the most important part is picking an attractive piece of wood, and paying attention to nice finishing.
a shaping tool. (bandsaw, hand saw, chainsaw, hatchet, plane, belt sander, mill, your teeth etc..)
a large forstner bit (either 1 1/2" or 1 5/8" - I'll explain the importance later)
Disclaimer- use common sense or succumb to evolution.
Step 1: Aquiring Materials
It can be any shape or size you like, as long as it is wide and deep enough to fit a tea light with a little extra on either side, as for length, it could be long enough for 1 to 100 candles.. but I think odd numbers of candles looks best.
I made two, one from option 1, and one from option 3
1) Firewood from your woodpile. Make sure it isn't rotten, nor does it have woodworm or other defects unless you think they may look good.
2) Go to a lumber yard or equivalent and tell them what your trying to make, they can probably give you a scrap for very little or free.
3) I met a tree surgeon who was working on a street near my house. I asked him for a fresh log, that was in the back of his truck. I had to call him a number of times as he was an old guy who seemed to be hard of hearing- don't give up! He gave me a maple log for 2 bucks.
- This is where the bike comes in, I was riding home when I met him, so I carried the log home bungee corded to my bike. Be careful, as its impossible to steer, and you become a very nice projectile.