I use about a cup of sea or canning salt, a half cup of brown or cane sugar, a couple teaspoons of onion and garlic powder, and that's it. I use a smaller Igloo cooler I have that holds the turkey and brine and fits in the fridge. Usually I like it to brine for more than a day, but less than 3. I always smoke our turkey, but after that the grill is the next best thing. I've found that stuffing the turkey makes the dressing really salty, so I put that in an aluminum pan and throw it on the smoker for an hour or two if I want my dressing to have some smoke flavor.
Even better is the hot dish I make with leftover turkey. I cut up maybe 2 cups of chunks of smoked turkey, a couple pounds of asparagus cut into chunks, 2 cans of cream of chicken soup, some garlic, some shredded cheddar cheese into the mix, and mix that and then top it with French fried onions. It's really good.