I use chile oil in dressings/marinades and as a finishing oil for sauces/dishes. You've heard of finishing a sauce with butter, sub in chile oil instead. Also great in popcorn or to rub meats with prior to using seasonings like salt/pepper, etc.
Depends on if it's more of an oil or more of a sauce. I've had some "oils" that are in jars and are best served with a spoon because they are more like a pepper sludge. Then I've had infused oils, and I like the tall skinny olive oil type bottles with the "bartender" spout. In the middle, I'd go with woozy or swing top.