I always get an assistant when shooting interiors to help with lighting and misc chores. It helps a lot to have someone else take charge of tiding up, taking care of equipment & setting lights/adjusting power etc. Myself is already pouring over the angle, lighting setup, the details & conversing with client.
Problem is many people are not professionally trained in assisting and they have this notion or mentality their job scope is something else entirely (example: being a photographer). As such so far I only work with people I know & trust. It'll be nice to get to know more people (assistants) but can't be sure how long they will be in this line of work. And one can't train a complete newbie much on an ad-hoc basis, because when they don't have an opportunity to practise nor see the result, they won't understand what how and why.
Back when I was learning to assist, it took lord-knows-how-many jobs before my ex-boss didn't have to keep repeating himself nor walk over to double check my work. I had to understand his style of work and entire workflow from setup to shooting to post process before I had a smudge of confidence of what I was doing while assisting. As for doing post, that learning curve was even tougher and definitely not something one can just throw to a stranger.
If you're serious about assisting then go full-time. Even if you have to start lowest rung in a studio to sweep their floor it'll be an experience. Otherwise I think you'll always be the assistant carrying gear and not doing much of anything else.
