As most avid tea drinkers will tell you, if you are using tea bags, you can get extra use out of them if you are willing to do so. Most people just chuck them into the trash, compost heap, or recycling bin, but saving them for your next tea is also an interesting idea.
A tea bag can be reused one or two times. After that, it's spent. Reusing green or white tea works better than darker blends. I usually reuse Orange Pekoe tea bags because I use two bags in one cup: I like strong milk tea in the mornings, with milk, no sugar. Once I've infused a cup, I'll keep the tea bags for my next cup. Then, I'll infuse both bags again with one new tea bag. The resulting second cup of tea is only slightly less strong than my usual cup, but perfect for the afternoons when I don't need too much caffeine.
Reusing tea bags is best reserved for tea drinkers who drink a few cups a day, otherwise keeping the tea bags becomes an issue.