Here's a few pointers (as I've found so far):
- How much are you willing to work? Sometimes shops only pay $8-$15 and some can be quite tedious and require you to drive greater distances. If you live in a populated area, there are generally more shoppers in that area and therefore less jobs available within a close distance. Rural areas are just the opposite. I keep a spreadsheet with information such as: total commission paid, non-reimbursed purchase cost, total miles driven (with a cost-per-mile calculation based on your vehicle operation cost, including gas, maintenance, etc.), and total time required to complete shop (including driving time, report entry time and shop time). I take this information and figure out how much per hour I'm getting paid. As long as you can keep this number at an acceptable amount (mine is $10/hr because it's supplemental part time income), then it is "real" and valuable income.
-Register with as many FREE sites as possible. There are a lot of sites that will charge you for their "listing" services. While this service may (or may not in some cases) make it easier to find available shops/jobs, this work can be done yourself by spending some time online searching. This will give your more opportunities to maximize your efficiency and pay per job.
-Get a Paypal account and a Paypal credit/debit card. Many of the companies pay through Paypal. While you can have the money transferred for free to your regular checking account, it causes you to wait a few extra days to access your money while the funds are in transit from Paypal to your bank account. Having a Paypal card allows you to spend your payments immediately through a Mastercard (and it's free as long as you run it through as a credit card and not a debit card.)
I hope this helps. Good luck!
Matt