Re: how the **** do you do this?
Yeah, I'd agree with buba. Parts bikes are the best source. Look carefully at some different frames and you'll see what I was talking about.
And ALL serious bike builders use some kind of jig for frame building.
No way you will build anything real straight without a jig, and it's fairly easy to build crooked WITH a jig, so....
If more is better, then too much is just enough.
If you can't afford it, build it yourself.