Sometimes I go through email, open a bunch of links as things to follow up on. I keep the tabs open until I've finished with them. I also keep tabs open per doc I need to review, code review still pending completion, etc. For a given project I keep a host of tabs open for things like documentation and research. Organizing these ephemeral tabs into groups (docs, code reviews, project abc, etc) keeps me organized. It's far more lightweight than bookmarks and works great with tab search. It keeps me from losing track of things while also being able to focus better.

Think of it like organizing papers on your desk vs putting them in the filing cabinet.