I've done some levelling on a couple of necks. Still just at the start of the learning curve, but it's something I have wanted to learn for some time, but had been nervous about it, so it's good to finally get stuck in.
The only "decision" you have to make is where exactly to set the truss rod before you take the beam to it. Good necks you can just use the notched straight edge to set it flat and you will get a great result.
You mark the frets tops with a sharpie then let the bar weight do the work, until you see that the frets are level.
Shaping the frets didn't take long to learn. After you do a few you will get a process down. I wouldn't advise using those special fret shaping tools as they will get dull before you finish the neck; its better to just learn to do it with files. My set of diamond files have done nearly ten jobs and work like new.
Jumbos take considerably more work than traditional frets, fwiw.
I believe the quality of the work comes from the analysis you do up front (where exactly to set the truss), and having a jig that perfectly supports the neck, and a perfectly level beam. There is an Erlewine jig that can pre apply pressure to the neck so you have another degree of control, but even without that I've been able to get clean action comparable to plek jobs I had previously.
