Establishing Initial Timing

Gentleman, I have humbly come here to ask for a bit of experienced advice. I know my way around a garage, but I have just realized that I have never truly had to "tune" the timing on an engine. This is the first engine that I can't just set the initial listed from the manual, run a vacuum advance and walk away. So my question is what are the tried and true methods for the at home mechanic to dial in initial timing and curve for a given motor? I have seen other guys post up every tiny detail of their build, and the senior guys here suggest settings. What I'd like to know is how y'all are establishing that. This is my first legitimate performance engine, and I want to learn. Feel free to post any links to the world wide webs to videos, articles, sites etc that dig into it. Thanks in advance! Joe