I'm not sure what you're selling, but typically weekends would be better because people are off of work and can come spend money. Also, if you juststarted, you probably haven't built any relationships with clients yet. Once you build up a strong clientele, you'll be better off. I was working at ahigh-end department store for a while and made about $30-40k/year (averaged out) part-time while in school. Of course, some days I would make a bunch, andother days would be borderline charity work.
To answer your question, though, there is no "usually make"--that's the double edged sword of commission. I worked alongside some people makingsquat and some people taking in six-figures.