That's a tough one man. I suffer from slight acne (a few pimples here and there) while taking any test, and to be honest I don't think there's any magical product to help. A lot of people will take an antibiotic like doxycycline, but with longevity of use you start worrying about all of the good bacteria it may be eliminating as well. If you typically don't get acne when you aren't on cycle, chances are hormonal fluxes are mainly the root cause, so the only way to avoid it is to not use exogenous hormones
Best suggestion is to be as religious as possible with injection timing to avoid the most variance in hormone levels. Since you're using short-acting esters, daily injections at lower doses would be best, but if you do EOD, just try to be as consistent as possible with always pinning in the morning, evening, etc.
FWIW, I do think using a well-reviewed anti-bacterial bar soap and a loofah to wash daily can help. It has for me at least. Just keep in mind that if you do have pimples, DON'T WASH THEM HARD. Very light for the sake of exfoliation. Acne is a bacterial infection, washing hard just opens the possibility of spreading that bacteria over a wider area. Also, if you can do your daily wash after the gym (immediately washing away sweat and everyone else's bacteria you inevitably encounter in a gym), I've found it to go a long way to preventing future breakouts.
Hope that helps.