The "bookmark" feature (next to the star in the web UI) may be the least loved and mentioned feature in Mastodon, but it's darn useful.

1) Hm, I might want to read this later. -> Bookmark

2) What a great picture! -> Bookmark and Fav and Boost!!11

3) Do I want to follow this account? Let me take a look later. -> Bookmark

4) I should boost this again sometime. -> Bookmark

Search (somewhat deliberately) sucks, making bookmarking essential to find stuff again. Use it liberally. :)