I think accounts should not be able to upvote their own content but that will only lead to users having separate accounts for posting and curating.
The only other option I can think of is having accounts upvote their own content, both posts and replies, by default so that users do not have to make the conscious decision to upvote themselves.
PS: I will be upvoting this reply when the 7 days is about to elapse so that I don't offend anyone but still get the few cents from my upvote.