@wig- there are some threads where @jea48 has weighed in with some excellent tips, all in keeping with Code. This summary won’t do the subject justice, but:
look for the quieter leg if you are in the States, the one with fewer noisy appliances, like refrigerator compressors, HVAC, etc.
use a separate breaker box if you are tight, with a copper buss bar;
oversize the gauge of the cable runs
don’t bundle the in wall cable runs
use hospital grade receptacles- the Porter Port is a good modestly priced unit meant for audio
have your electrician pull a permit consistent with local code
have the electrician double check your existing grounding while the work is being done.
make sure the receptacles are in phase.
newer installations may require Arc-fault breakers and possibly, child proof receptacles.
I’ve had much better luck with commercial electricians. I’m sure there’s more, this is what came to mind off the top of my head.