never lend what you can't afford to lose.
Work friends would be the easiest. The rest, good luck!
it depends. if you have a really good friend and you give him about $10 dollars he probably wont give it back. (from self experience)
If you want it back don't loan it out.
Dont lend money, either give it with an open heart or dont give it at all. Lending doesn't benefit anyone, you or them.