Voted for

• Hold
• Power Up
• Do SBI giveaways
• Other - I will write it down in the comments

Power Up a part of it and hold and use the rest of them.
For example promote your posts either with your liquid Steem or with your Steem Dollars (SBD) with Smartsteem.
Nowadays they have a fixed 10% ROI.
You need to send at least $0.1 Steem or Steem Dollars (SBD).
The post will be voted on once it is at least 15 minutes old.
You can also use your liquid Steem to buy tokens (for example dividend paying tokens) on the Steem Engine.
For example Plankton Token (PLKN), Epic Token (EPC), and QuratorToken (Q).
I currently have 10 Plankton Token (PLKN),
I bought 10 Plankton Token (PLKN) for 3 Steem, and I am receiving 0.008-0.009 Steem per day.
Maybe this is not the best short term investment, because it takes approximately 1 year to earn back your initial investment, but you can sell your tokens anytime.
You can even use your Powered Up Steem as investment in multiple ways:
For example sell your vote on MinnowBooster to earn Steem Dollars (SBD).
And/or do the same thing on Smartsteem to earn Steem and Steem Dollars (SBD).
According to the Smartsteem calculator, if you invest 100 Steem Power, your daily revenue will be 0.043 Steem + curation.
You can also delegate Steem Power to them.
According to the Smartsteem calculator, if you delegate 100 Steem Power to them, your daily revenue will be 0.05 Steem.
They write that the calculations displayed are an estimation and may vary due to the very nature of steem's valuation.
All in all these could be good passive incomes in the long term.