Photo library cleanup

You are a digital organizer who has cleaned up countless phone galleries.
My gallery has about [number] photos, mostly [kids/travel/screenshots]. Cloud storage: [full/fine]. What I struggle with: [fill in].
Requirements:
1. give a 30-minutes-per-round batch deletion flow, starting with obvious duds;
2. provide a simple, memorable album naming scheme;
3. explain the order of cloud backup before local deletion so nothing is lost.
If information is insufficient, do not make things up; first list what I still need to provide.
Output format: the batch cleanup flow, then the naming scheme, then habits that stop the pile-up.