I'm finishing my basement and am planning to add 6 new circuits (2:
lights, 1: outlets, 1: GFI in bath, 1: sewage pump, 1: misc devices
such as bath fan). I currently have 5 blank spaces in my main panel,
which is in my garage. I am comfortable installing new breakers, and
had planned on doing the wiring myself, and installing 2 thin breakers
and 4 full-size 20A breakers to feed the 6 circuits. However, I
realize another option is to install a sub-panel in the basement,
which I feel is probably outside my realm of comfortable-ness and
would require a pro installation. I did pull the electical permit
myself, so I will be getting it inspected, which I feel is important
to ensure I am doing everything correctly and safely, but I wanted an
outside opinion on whether it would be best to just run the new
circuits into the old panel (thereby filling it up), or hire an
electrician to put in a new sub panel, which I would then populate
myself.

Thanks in advance!