Post hardfork 20, there are two curation-related changes:
Most people who paid attention to these changes should have noticed significant increases in their curation rewards since HF20.
Why? Because there are a lot of early voters apparently, and the 2nd change apply. The curation rewards that would have gone to the author now returns to the reward pool, which increases. Plus there are less active people on a regular basis to share the reward with. At least that's my theory.
When it comes to self-voting, before HF20 authors who wanted to maximize their curation rewards upvoted their posts immediately after publishing.
Now, with the new system, that would be wrong, and they have to wait until around the 15 minutes mark if they want to self-vote.
I don't self-vote, even if apparently that might be in my own interest to do so, reward-wise, after 15 minutes.
But I made a pledge not to self-vote unless absolutely necessary a while ago and I respect it.
However, I am in the curation trail of SteemRomania community. And as such, I receive "self-votes" when my content is being upvoted by the Romanian community.
For people following curation trails, it is important to make sure your vote isn't too low, or you will end up not receiving any curation rewards, because your vote might enter the category of votes below the dust threshold, and be worth nothing (and you as a curator probably won't get anything either).
This is a pre-HF20 post by 
@crokkon/how-will-the-hf20-dust-vote-changes-affect-the-vote-values
Also, an interesting note about voting on comments I forgot about. Don't vote a comment with less than $0.02, unless it already has some votes and your vote will make it go above that threshold. Here are more details:
@crypto-econom1st/usd0-02-dust-threshold-for-upvote-value-don-t-upvote-comments-with-a-value-below-usd0-02
A little different about posts, because they are more likely to go above $0.02, but if they aren't, these are also wasted votes.
There are some Steemians who treat curation as a science, and probably earn a bigger ROI this way.
But from my own experience, manual curation can be pretty rewarding at times, even if you don't hunt curation rewards, and only upvote what you read and like.
What are your preferred curation methods? Automated? Manual? Through engagement/comments?
