I've used Butler Creek caps on all my scopes and do not open them untill it's time to shoot....as far as binos I use cat crap and it works decent....it's really hard to keep them completely fogproof...I have a bino cover zip tied to my binos and when im not using them the cover is always on keeping them dry. Also when it's cold and wet out and your glassing try to not breath on the lense as that's a major factor in fogging.