I've only done this once or twice. The one we did that we liked the best had a bunch of fresh herbs rubbed under the skin. Frying it really sealed in all that flavor. I think we injected it with some herb butter as well.
BIGGEST TIP: Be careful. Deep fried turkey has increased the number of Darwin Awards greatly over the years. Make sure you don't have too much grease in the pot. Well before loading and heating, put the bird in, just cover with water then remove the bird. Note or mark the top of the water at THAT level and put only that amount of oil in. Spilling hot oil all over the propane flame is dangerous!
Big JT's Smokin' BBQ Competition Team
"The path was worn and slippery. My foot slipped from underneath me, knocking the other out of the way, but I recovered and said to myself, 'It's a slip and not a fall.'"