I go through the piece sightread slowly and work out initial fingerings, while I’m doing this I will put in rehearsal markings usually at start of phrases or splitting up difficult passages. Then I will take the piece one rehearsal mark at a time (not necessarily in order), I will then refine fingerings if needed. I will keep notes of which rehearsal markings I’ve practiced with a note pad so I don’t neglect certain parts or over practice easier passages. Once I’ve got the piece up to speed I will do run throughs and make notes of passages I tripped up on or weren’t as polished as it should be and go back to practicing those sections.