Is it correct to upvote my own posts?
I usually don't do it unless I set a beneficiary. People have differing opinions, but people are mocked for liking their own stuff on other social media, why should Hive be any different? Voting your stake should be about rewarding others, not yourself IMO.
How about to upvote my own comments?
Normally no. One exception would be if there are many comments under your post and you want to float an important one to the top.
How about to comment on my own posts?
This is fine in circumstances where you want to add some information, but don't want to muddy the waters in your post. Under most circumstances though, you can simply edit your post.
Thanks for replying (and even quoting my questions so nicely, great touch.)
So to make sure I understand:
Lean away from upvoting our own posts. If you've set a beneficiary, that's the 'best case' for upvoting one's self, but opinions differ.
Lean away from upvoting our own comments, unless maybe there's an important one that needs to float to the top of thread.
Self-commenting is fine, but editing the original post is likely better (this matches with @marc5 's answer too.)
Very helpful and insightful, I'll include this in the guide. I've yet to see it explained clearly for beginners. Thanks for replying/upvoting!