Any and all mascara tips?

please help:) i really need tips on how to get mascara full and long and lots of volume. normally when i try to like keep putting it on, my eyelashes clump:( i have at my house great lash (pink and green) and colossal volume express waterproof (the yellow one) and falsies. any tips? i also wear eyeliner on the top, and onthe bottom sometimes. and can i put mascara on my bottom lashes, because i heard that ruins ur lashes? thanks:)