Cut your garden bill for next year by not planting all the seeds just because you have them and instead save them for next year. I just planted some seeds for transplants from last year's batch and they all came up, so I can attest to the efficacy of this way of storing seeds.
Keep your seed packets from not getting damp and leaving them out in humid air. (Don't lay them in the dirt in the garden). Store unused seeds in their packets in a ziploc bag in the refrigerator whenever they are not in use. Do not put in the veggie crisper because the gasses of some fruit and vegetables will interfere with the dormancy of your seeds. Put something in the ziploc bag to absorb any moisture that finds its way in there, like the silica gel packets that warn you "Do not eat!" or dry milk powder. Store them in the refrigerator until next season.