I used to upvote my own posts until I found Steem Follower. It's a vote exchange where you earn points for upvoting other people and people earn points for doing the same for your posts. As your posts are upvoted your points go down. When your points get to zero your posts stops being available for upvote.

It's better than upvoting yourself because you can help out a fellow steemian, get a bigger upvote than you could give yourself(because now you get upvotes in exchange for all your upvotes), and you still get your curation rewards for your upvotes.

Here's the link: https://steemfollower.com/?r=4476