I think the main thing is making sure the pollen is completely dry, ive went as far as placing pollen in a small room or closet with a dehumidifier and getting the humidity as low as possible, then the container im storing in has to be completely air tight. I like to triple bag my plastic vials with good brand name freezer bags vacuumed tight. Also a good desiccant, I’ve used everything from rice to water storing crystals. You know when you pick up a vial and the pollen don’t move it’s garbage.Looks great! Silica packs will help. Make sure the pollen is dry before storing. I keep my pollen in centrifuge vials