Maybe it's a little 'low end' for you, but if you get desperate for some cash...

In most cities there is an area on a main drag where people hang out as 'day labor'. I'm sure it's all under the table income. You just wait with the group of others and watch the vehicles.

If a truck/car slows, watch it closely. The 'language' used to be that the truck driver would wave a $20 bill and hold up the number of fingers of guys (usually) he wants. Then he leans across the seat to the open window and yells what the job is, and what it pays. I think most of it is manual labor: cleaning weeds off a vacant lot, chopping up a fallen tree, etc. Sometimes he will point at specific guys, probably because he's used them before and they did a good job.

In this as in all things, PAY ATTENTION. If you get a bad feeling about the guy or the job, just smile and back out, citing a bad leg, bad back, etc.

Sue