I was using one of my of my home made drills today drilling some pilot holes through hardwood and thought it possible that not everyone knows how to make them. Firstly I should say that they work just as well or better than twist drills in wood. They are made of motorcycle spokes or if you need small ones bicycle spokes.There always seems to be a junked motorcycle around somewhere or failing that a wrecker would probably give you a bent wheel, it's no use to him.
Cut a spoke out of your wheel with a grinder, if you can use side cutters the spokes are probably soft and you'll have to harden and temper them ...which is more than I want to do usually. I take the spoke and cold forge it flat ... any steel hammer on a hard piece of steel but even a piece of soft mild steel will act as an anvil. The newly flared area will be a around 2mm or 3/32" wider than the original spoke.
I then take it to the grinding wheel and work two bevels coming to a point at the tip .They can be pretty crude too...with my eyesight that is guaranteed. Probably a 30 degree angle on the relieved faces. The photo might help but it's hard taking photos of small things with cheap cameras!
A couple of test holes to see if my sharpening was working . This drill will drill a 3/16" hole 3 1/2" deep in hardwood in 20 seconds .You will have to pull it out once or twice in a hole that deep to clear the swarf.
This idea was shown to me by a boatbuilder about 40 years ago, drill bits were expensive and wages were low. The bloke who told me the trick never bought small twist drills to drill rivet holes in a carvel hull. A small drill bits were bike spokes, his bigger ones, up to 5/16" were motorcycle spokes.