Having read a few posts from more experienced members of the Steemit community such as
https://steemit.com/steemit/@steevc/hey-steve-why-didn-t-i-get-a-vote-from-you and
https://steemit.com/voting/@shanibeer/thoughts-about-voting
I've realised that self voting comments is sort of frowned upon.
Now this is far from obvious to a newbie because its very difficult to get any attention on steemit without spending big SBP on huge bot upvotes and one way is to write interesting, relevant comments on more popular posts. Its natural to want to use you 1 or 2c worth of upvote to get your comment up the list where it is more visible.
But as this is appears to be bad etiquette, I'll stop doing this.
Please forgive my high self-vote percentage.
I'm working on lowering it. :-)