I think something that may help is having some sort of a "author voting power" basically when you vote on someone it would vote with a percentage of your vote with a formula like; percent of last x amount of votes that did not go to that same author.

For example, if I have self voted 50% of my last x votes, my vote would be worth 50% of what it normally is worth.

The problem with saying "no self votes" (I know, you're not saying that but some people are) is that people will just create other accounts to self vote themselves. With my proposed solution it would counter that work around as well.

I would think that this would encourage people to spread around their votes more or at least give you less and less weight everytime you vote on the same person.

I would love to hear your thoughts! Keep up the good work! Sorry about that whole flagging mess earlier! I'm glad you took the high ground!

Edit: I decided to write a post about this https://steemit.com/abuse/@littlejoeward/stopping-self-vote-abuse-another-proposal-voting-power-per-user
Enjoy! ;)