You can make handles by hand very easily. But there's a couple of things you should do when making them.
1. If you're making a handle for a tang tool, drill your hole first, before you start the shaping.
2. Then mount the block between two centers. You can make a simple jig to hold the handle block. Use two hinges to attach two arms to a piece of wood approximately the length of the handle. Then put a threaded rod that pulls the two arms together (another approach is to use an F-clamp to pull the two arms together). Put a screw (or nail) through each arm so that the point sticks out towards the inside. Mount your blank between the two centers (screws or nails) and tighten the threaded rod (or clamp) to pull the arms tight. Then mount the jig in your vise. If you want to make sure it doesn't turn while working on it, you can drive a screw or nail through one end to hold the blank in place (there might be better ideas out there).
3. Then attack your handle with a rasp, spokeshave, or whatever you want.
The advantage is that the handle will be "centered". There's nothing worse than a handle that's off center when you're using it.
Mike