Upvote your own posts without prejudice, as long as you write something good, I don't see any problem with it.
What I DO have a problem with is people who right "Good post!!" and upvote themselves and then call the bots in to upvote that post too. "Thanks for posting!!" and "Good post!" spam are not $1.00+ (or even $0.01+) comments.
It's happened a few times and I take great joy in downvoting them.
Yups agree that is def worth a downvote! You are doing a good job there downvoting to discourage people doing so!