Every year, while I'm enjoying my best and most delicious garden tomatoes, I save the best seed for planting the following year. I've enjoyed amazing tomatoes, handed down and passed around, year after year. No matter the source, if I have a good tomato, I save a seed or two and give it a try the following year. With hybrids, you're never quite sure what you'll get, and I enjoy the surprises. With heirloom varieties, you get the same great flavor, year after year. I even try to improve on that, by always saving seed from the best tasting tomatoes off each plant.
Here's a quick and easy way to save tomato seeds:
1) As you've sliced into a winner, grab a 2-3 inch sticky note and write the name of the tomato on the top. If you don't know the name, make one up. I name tomatoes like "Really Big Pink" or "Gina's Favorite's" or whatever will help me remember the variety.
2) Scoop a few seeds out of the tomato with the tip of a spoon. You can keep the goo on them (it helps them stick).
3) Place the seeds on the sticky note (see photo).
4) Let air dry for 1-2 weeks.
5) Place sticky note in a baggy or mason jar in the fridge.
6) Next year, pull them out, peel the seeds off the sticky note, and plant indoors (AeroGardens are great for this) 6 weeks before the last frost date. Then repeat next season!
Extra tip: The sticky note above shows my current "favorite tomato ever," a readily available beefsteak heirloom variety named "Cherokee Purple."