Many people have old jewelry sometimes stuck in a box in a drawer, if you go to garage sales ask if the have any old jewelry, they may not put it out, but if you ask they may drag the old box out. if you work where a lot of women work ask them if they have any scrap jewelry they would like money for, you could advertise in Craig list stating you buy or will trade for scrap gold, sometimes you can find sterling silver in the second hand stores some worker overlooked, I have found a couple of ounces that way, I bought some dental gold (teeth) from an auctioneer/antique dealer, he had coffee cans full of dental gold teeth (I wished I could have bought more than I did), I have bought karat gold and sterling from a gold buyer/coin dealer, buying it for melt value (this gives me material to work with and since I just buried the metal till the price rises or hard times, I will get my money back or more later), jewelers scrap is another source, some jewelers will sell some scrap for what they get from a refiner, sometimes they have material that they do not get refined or Know how to deal with like carpets, bench sweeps or vacuum cleaner bags and so on, read Hokes book, she will give you the knowledge which can be helpful when talking to a jeweler. If you live in a mining area put up an add in your local mining supply store, stating you will buy fine placer gold.
Its like when you want apples you keep your eye out for the apple trees.