If you have some packets of flower or vegetable seeds that weren't completely used, they will be fine for next year if you store them correctly. Fold the top of the foil or paper packet over several times to exclude air. Then place in a zipper-top plastic bag and remove as much air as possible before sealing. Store in the refrigerator, if possible. If you must keep the seeds at room temperature, choose a spot with cool temperatures and low humidity.