1. Don't save because you just want to save. Save what you think will be useful to you. I went through that stage and I had my account full of bookmarks with 80% of them saved just because *I might need them* while other alternatives are just the same if found via Google.
2. Practical method; double tags: save read later items as usual but add a special tag similar to "top" in addition to the main tag(s) so when you want to find the top wanted read-later items, use both tags in the search field as tag+top. You might have a lot of items sharing the same tag but top will be surely unique and the only items will be shown are the ones with both tags.

I'm curious if anyone is in the habit of prioritizing their bookmarks to read later. If so, what sort of approach has worked for you?

I tend to save lots of random pages to read later, and that list gets to be quite long. But sometimes I'll come across something I really want to read ASAP, or something with a deadline (e.g. ordering concert tickets). I tend not to save these pages to PB, because I'm afraid the important links will get lost in the big list. Instead, I email them to myself or write them down somewhere. This is exactly the sort of habit I'm trying to avoid in the first place!

I'm thinking of creating some special tags for priority, but first I'd like to hear what other people think.