I've got a decent vice bolted to a good bench. And got two different style benders. And to do a 90degree have made a very simple modification to the vice to make the job very simple.

Clamping the wire directly in the vice will wind up killing it at the sharp jaws. So I chamfered one of the jaws. I basically rounded the sharp edge on the side I pull down the wire. That removes the stress riser that the edge introduces into the wire as it's being whacked with the hammer. And the wire bends down nicely.

I've also gone a step farther and drilled a groove down both jaws that orients the wire to be perfectly straight up when the jaws close on it. It's foolproof to slap the wire into the vice square and true with no aligning needed. No technique required. No pads to juggle. Just close the jaws and start whacking. BTW, I actually do most of the bend with a fairly large scrap of steel I got that levers against the vice, but that's not really needed, just convenient. To get the 90 requires a few hammer thumps.

To drill the holding groove is easy. Clamp a piece of wood that's slightly thinner than the wire diameter. Center the drill in the wood and drill straight down. Each jaw face gets a shallow groove. Aligns and holds the wire better and easier.