Like spices and herbs, I have the tendency to keep tea far too long. I have over a dozen flavors in my pantry, slowly losing flavor. Add to that all the tea my mom kept, and it's at least a year's worth. It's going to stain my teeth, and I'm not used to this much caffeine, but I'm going to have to start drinking more tea.
The key to iced tea is to sweeten it while it's still hot. Of course, it means you're sweetening it how you like it, and everyone else just has to deal with it. It's simple chemistry that sugar will not dissolve well in cold liquid. A decent alternative is keeping a bottle of simple syrup on hand and adding some of it to the iced tea. To make a simple syrup, boil equal parts water and sugar, then cool slowly. It's like liquid sugar, does not need to be refrigerated, and you eventually learn how much to use to get the desired result.
For hot tea, it is important to steep the leaves for the right amount of time. Too long, and it gets bitter. Not long enough, and you miss the rich flavor. And don't reuse tea bags on a second or third cup. You might as well be drinking hot water. Brew it in a pot instead, remove the tea bag when it's ready, and reheat it later if you need to. The best way to use leaf tea is with a tea ball or a nifty little tea sieve that only rests in the pot as long as you need it. I haven't used a French Press, but I've heard they are also ideal for getting a proper brew. Dumping leaves in and using a strainer only really works if you plan to serve the whole pot within ten minutes and start over for a second round.
I'm going to try to drink my oldest teas first, but so many of them have been there for over ten years, I'm not sure where to start. Teas in sealed bags or tins keep longest. Wooden boxes are more subject to humidity. Tea does not "go bad" if protected from humidity, but it loses flavor and aroma. So, next time you are tempted to buy the extra-large box of Lipton at Costco, ask yourself if you're really going to drink 72 bags' worth in six months.