You don't use aromatics in the cavity
It sounds like a statement your dentist would shame you with, but in reality, if you are keeping your chicken in tact while cooking, it's definitely worth your while to stuff the cavity with fresh herbs, peeled garlic, diced onions, and even lemons.
The flavor will soak through the whole bird while it cooks, delivering evenly flavored meat, with an extra kick. The choice of seasoning is yours, of course, but you might want to keep in mind that some critics claim this kind of "inner seasoning" may make the skin less crispy... but in our experience the difference is negligible and the benefits well outweigh the risk.
You aren't burnishing the bird with fat
So you don't necessarily need to add extra fat to your chicken -- just like you don't need to eat a tube of cookie dough and watch three episodes of The Wire before you go to sleep every night. It's just better when you do. Drizzle some olive oil, or a melted stick of butter, all over your chicken before you roast it to give it golden-brown skin and, um... fatty taste. Trust me. It's delicious. Or, you can coat your fingers with butter and (carefully!) peel back the skin and coat the inside of the bird with some butter between the flesh and loosened skin.