Stick a half lemon in the cavity for one thing - keeps the juices flowing. Make a decent gravy with the outpourings too - that will perk it up.
Start with the absolute best bird you can afford - any 2 for a fiver rubbish will taste useless and need a jar of chemicals like Chicken Tonight to get any taste out of it.
Rub with a garlic dressing. Also lift the skin over the breast and rub over with butter before roasting. Add some goood herbs like rosemary and thyme (or lemon thyme for variation0 in the cavity which will infuse a flavour.
Roast over a bed of diced root veg. and drape streaky bacon and paprika over the breast - cover the bacon until the last 30 mins of cooking to stop over doing it. Roast with decentchipolats too for extra taste.
Always give the bird 15 mins at least resting before carving to allow the meat to relax. this will also improve the flavour. make the veg and gravy while it is sitting.
Try the 40 cloves of garlic recipe -
http://thefoody.com/int/chicken40.html is one version. You can joint the bird or leave whole. The result is a creamy infusion of garlic with a soft aroma, not a stinking heap of garlicy poultry. Try it!!