Here below some hints about what I consider some interesting ways for to invest one's Steem Power.

Do you know a best way? Well, please feel free to suggest it in comments.

MinnowBooster

<<Delegate STEEM POWER to the @minnowbooster bot and get roughly the returns you would get if you voted up only your own posts, but without the shame! You will earn and be paid daily with a prorata share of the funds paid by users for @minnowbooster to up vote their posts, less our facilitation fee. You can always undelegate but will lose the earnings for the current unfinished day.>>

SmartSteem

<<By delegating to smartsteem - you earn profit on the votes made through our bid-bot. We pay out 90% of the profits to our sponsors proportional to the delegated amount / total delegations. the amount can be lower right now due to the bid-bot being newly released and not yet listed on the bottracker>>

AppreciatoR

AppreciatoR is at the number tree place in the "top delegated chart list"

How to manually delegate and un-delegate

Delegate

Un-Delegate