Here is how I make sweet tea, and I ain't had any complaints:
1. Take a half-gallon pitcher and fill it approx. 1/4 way full with water. Add 1 cup of sugar and stir. This helps to melt the sugar while you are waiting for the water to boil.
2. Take 2 family size or 6 regular size tea bags (Luzianne is superior to Lipton) and put them in a regular size cereal bowl or teapot.
3. Fill the bowl with the tea bags in it with boiling water. The way I measure steeping time is like this: as soon as you pour the boiling water over the tea bags, go outside and smoke a cigarette. Don't linger, but don't rush either. By the time you're done, the tea is steeped enough.
4. Pour the bowlful of tea (without the teabags) into your already partially filled pitcher of sugar-water. You can squeeze the excess out of the tea bags using your spoon if you want, depending on how strong you want the tea. Stir while you fill the pitcher the rest of the way full with tap water. Doing it this way keeps you from having tea that's too warm and melts your ice too quickly.
5. Your pitcher of tea is best if it sits for a couple of hours, but when you get tired of waiting, pour yourself a big glass (already full of ice) of some of the best tea around.
The secret is 1 cup of sugar and 2 family size/6 regular size tea bags to the half-gallon. 1/2 cup sugar just won't cut it, but doing it my way, you won't end up with that too-sweet, syrupy tea, either, that you sometimes run into in BBQ restaurants.