I usually make small adjustments to the VE Table. The Megasquirt data log viewer has a "VE Analyze" feature that will take the data in parameters you set and adjust it to help it reach your target AFR. I use this a lot, its quick and easy. Sometimes it needs a little smoothing out but usually its suggestions are very good. Then when the car is running I allow it to make a certain % of change to help reach the target if for some reason the tune isn't spot on.
I seldom to any manual tuning, if I am working directly on the VE table it is for smoothing adjustments or a flat spot. The tools the log program has can really nail things down. It can also adjust the table live with the laptop plugged in but I only use that if I make some big change. Its a quick way to point things in the right direction.
I like megasquirt, its dollar per feature is amazing. However I think Holley has huge advantages in the software and self learning department. I thought I had a problem that would require replacing my ECU. I priced a dominator out which is what I would need to match my features. Just the ECU with no wiring or anything cost way way more than my entire electronics package.