Soups and stews just lack flavor without a solid base of stock. So I always try to keep some around, in the freezer. I'm not sure this is something I would do if I could buy stock. Unfortunately, it isn't something sold here, bullion cubes yes, but they can make things too salty. The great thing about stock: it's great way to use up fruits and vegetables that have seen better days and of course you know exactly what went into it.
Fill with water and pressure cook for 1-2 hours (an hour is probably enough). Once it has reached pressure I put it on the very lowest setting on the smallest burner. Just enough heat to maintain pressure. 'Real' cooks make stock by cooking on low heat for 12 hours. If you have all day to make stock then it might extract more flavor, I've never tried it. It could be possible to do it in a crock pot, but I don't know much about them. The pressure cooker is my weapon of choice for these kinds of things.
Drain with a collander. Squeeze the muck to get as much juice as possible.I don't keep the meat from the chicken wings because it will have been overcooked and stringy (and it is a pain to go through and extract it). Chicken wings are dirt cheap, and they've already given their all to make this stock.