First convert it into SP. Then the lowest possible ROI you can get is to try to find best content creators to upvote and claim the up to 25% curation rewards.
If that isn't enough you can always shamelessly selfvote your own stuff 10x a day for max profits, but I wouldn't suggest that to anyone. That kind of behaviour is strongly frowned upon by the community and can lead to flags. So better skip this one.
The next thing you could do is to delegate to bidbots like @smartsteem, @postpromoter or any other and claim liquid STEEM/SBD as a reward for your support. This will return more than curating but less than selfvoting.
There are a couple of delegation based curation projects operating that will, when you delegate, upvote you once a day at x10 the amount of SP you delegated. So, if you delegate 1000 SP you will get a daily vote at 10 000 SP. Basically like selfvoting so it's still frowned upon by the community, less than selfvoting but still.
The best thing you can possibly do, in my oipinion is to delegate to @steem-ua which is a new reputation system for Steemians that upvotes its supporters (those that delegate) based on their UA score and how high their posts rank in the Algorithmic Curation Rounds. I wrote an article about @steem-ua that goes into detail about the project which you can read here:
There are different things you could do with the steem/and in your wallet. I know of two things that you could do, namely;
Lease out your steempower: @minnowbooster offers a service where you can lease out your steempower to them and they'll pay you a fixed amount weekly. It's not a bad investment to make and since you leased your steempower out, your investment is always safe.
Invest in private traders: Private traders like bank of Attat(@bankofattat) and Bank of Plethora(@bankplethora) on steemit provide trading services for people who can't trade for themselves and they pay you a particular amount depending on how much you invest with them
I hope you find this useful
If you plan to be a Steemian for a long time take a look at Steembasicincome and similar things. They give life long votes, even if you only post once a week. With additional curation you make the most out of your SP.