Should you strip meat off bones before putting them in a stock?
Meat can add a lot of good flavor to a stock, but it can cause a lot of "scum" to form, so you have to be more diligent in your skimming, otherwise you get cloudiness. The bigger problem with winglets is that they're mostly skin, which equals fat, which is generally not a good thing for stock. Again, though, there's a way to fix it: refrigerate the stock, then remove the fat that solidifies on top.

Other than that, there are the usual bits of advice-


Add a whole onion, skin on - the skin provides good color
Add flavorful vegetables: carrots and carrot-shaped root veggies, celery stalks
Cook low and slow
Do add spices (whole peppercorns, whole allspice), but don't go overboard with them
When scum starts to form, skim it off with a strainer or a spoon, whichever works better for you
Did I mention cooking low and slow?