Personally with those steem prices atm I am adapting every few days. Changing the percentages in the voting trails (as I would like to see at least 0.001 SP reward and not a ton of votes with 0 SP reward). So I keep track on that in Steemworld..
And I usually maintain around the same percentage with manual voting for every post and a lower one for comments. If I see that I have high vp I can make exceptions, but usually it's pretty steady with all the curation I do every day.