I do pre-drill, but the problem is that if the stock isn't a wide enough diameter, such as 3/4" to 1" square stock, there isn't enough slop room to allow the cut to right itself. I need to pretty much drill perfectly to begin with. I think I need some sort of drilling jig to keep things square.
Start with 1" stock (3/4 is too small you need some slop), use a wood spur and turn it down until the corners are just rounded off. Pull the rounded part out, take out the wood spur, and stuff the rounded seat blank far back into your 3-jaw chuck as you can and tighten your chuck, this will be close enough to straight. I used to have problem with this on my Sherline until I found I could stuff it back about an inch into the chuck. Anyway after that bore the hole to the desired diameter. Put it on a mandrel. Turn to final OD, about .680. There is no way there isn't "enough wood" on a 1 by 1 blank if you follow this procedure and don't get the wood too cockeyed in your lathe when you bore the hole. Use a magnetic base and dial indicator to check the straightness of the setup before boring the hole if you want to be sure.
Make a jig if you want, that would work, but you shouldn't need one if you follow the technique above.
