Okay so if I want to give 100% of a vote to someone and not get any curation at all, vote at 0.

Well, sort of. Even with SteemAuto at minute zero I'm finding I get a tiny bit of curation. But you're also giving more than 100% of your vote to the post author because of the 50/50 difference and the broken SBD peg. Self-votes are the same.

If I want to give 100% of my self-vote to the curators of my post, vote when?

You can only ever give up to 25% of your self-vote to the curators (and it's smaller if you've had immediate votes). To give the maximum possible just be the one to upvote last.