I'm converting my small two car garage into a shop. I now have only two
outlets in there plus the light circuit for the ceiling lights. I would
like to put in a bunch of 110V outlets for handheld power tools, movable
lights, and such things. What I cannot find out is how many outlets I
should have per circuit when I don't know what the load is going to be? Is
there a "rule of thumb" somewhere, or a "best practice" kind of thing that I
can use as a guideline? I need this both for the 110V outlets and the 220V
outlets since I'm planning to leave some open for future tools. I will
convert all my tools to 220V that can be converted , but I need to plan for
expansion. Or should I just run a separate circuit to each 220V tool?
Since I'm the only one working there, only one tool will be used at a time,
but the DC and the A/C unit, both 220V, will be running.

My shop is 20' x 20'. The main CB in my current panel says 150 so I assume
I have 150Amp service. Otherwise no labels or markings clutters up the
expanse of gray paint in the panel, so I guess my first job should be to
map out the circuits I already have. And finally, the panel is full. No
expansion possible. So I will have to put in a sub panel. I have room to
put it right next to the existing panel. Unless that is a no no.

Otto