I do the following to keep my sanity when doing something like rebasing a feature branch onto latest origin/master:

* First and most important: turn on rerere.

* Second: merge and resolve all conflicts, commit.

* Third: rebase.

The second step might look redundant, but thanks to rerere git remembers the merge conflict resolution. That makes step 3 have fewer conflicts; and step 2 tends to be easier on me, because we are only reconciling the final outcomes.

(Well, I'm lying: the above is what I used to do. Nowadays I let Claude handle that, and only intervene when it gets too complicated for the bot.)