The total rewards for a post are split between the author and curators 50/50. So, if you your post payout is $10, then you get $5 and the other $5 is split among curators (everybody who voted on the post) based on their vote hp and weight.
The $5 you receive are also split into 50/50. Half you get as hp, and the other half as HBD.
You are free to vote on your own content if you like. But it is better to use your votes on others since you receive 50% back anyway in curation rewards.
Thank you, now I know :)