I've got centering bits and even put on a new keyless chuck but they're still not perfect

My issue is holding the work piece...

How do you drill out a perfect hole in the center without a lathe? I have an entry level WEN dp, a decent vise but I'd like the hole in the same spot everytime. You guys build a jig? I'm also having a time holding my baffles, what do you guys use? How many bits do you use on a .390 hole? You know, s...