Would you be OK with Hillary as president? If yes, give approval; if not, don't. Order of preference simply doesn't matter in approval voting. The only reason it seems complicated is because we are too used to strategic voting in the First Past the Post system.

I recently had the occasion to really game out what happens in ranked choice voting. It is similar to approval voting (you should only rank people to approve of), but in practice you elect whoever gets past the 50% threshold first, which may not be whoever had the most raw approval. The first person past 50% is effectively random, especially in a large field with complicated voter preferences. So, you get an illusion of choice: everyone lists their preference, but the actual winner is a somewhat random choice amongst the candidates with >50% approval. Thus, I advocate removing the illusion, and simply picking the candidate with the greatest approval. Easy.

i wrote a page on this very issue.

https://www.rangevoting.org/RVstrat6