My technique is very similar to Koukouvagia's (surprise) - butter under skin (with herbs - i like crushed garlic and black, pink pepper and coriander seeds crushed roughly, plus very little fresh thyme.
I put it on a large flat low-sided baking sheet (1 inch or less border) lined with parchment paper. Turn oven up to 450. Dry skin with towels.
When oven is hot i put it in low in the oven - cooking till tests done (piercing, feeling the knife, seeing the color of the juices) - if it's a big bird (turkey, for instance, or the big chickens you get in the states) i might loosely tent it not to get it to burn.
The skin is crispy and tasty, the juices are kept inside and the chicken is incredibly moist.
I like the low sides on a wide pan because i'm convinced that having sides produces steam that sort of hovers around the chicken and that keeps it from crisping. Then almost halfway through i put in seasoned potato wedges and let them get nice and browned outside, soft inside. Oh no, my mouth is watering already. The wide pan allows me to cook the potatoes in the drippings and they come out so tasty.