Almost any brand of idiot can tell bad wine. Honing and expanding this sort of knowledge is almost as beneficial as knowing about good wine. The point being, if you can't look like a sterling socialite with your exquisite wine taste when serving the blood of the grape, you can at least avoid looking like an ass with bottle of funny tasting swill because you can't tell the difference. The same goes for all of these trendy wine-fruit juice mixes you see plugged on TV and glossy, chic magazines. If anyone of these people think that boxed wine is acceptable, rethink your relationship with them.
Wine tastes better when served properly and matched with well with food.
If you can make a combo work, however, buck the rules and go with what tastes good - rules of dining and taste etiquette are usually formulated by people too daft to experiment. If you want to try mixing and matching, your best bet is to try a lot of wine with a lot of food, while not getting too woozy to remember what went well with what. Wine-food matching guides are available if you really get stuck. Don't experiment too much in the arena of temperature, however - especially by serving red wine chilled. Cold red wine is like a cold kiss, better left undelivered.