first steem power is the value of your upvote in $
as much as your steem power is strong , as much is your upvote value is high (in $)
so first tip is to make your steem power strong ,
how to make steem power stromg ? you have 2 way :
1- collect your rewards in steem and buy steem power
2-buy steem then buy in it steem power.
so your upvote to your posts will give you more money and your upvote to your friends also !