Cynical old lag English teacher answer? Stickers. & cunning timing.
Obviously, the stuff you have to mark properly, you have to mark, but the stuff that's just SLG being twitchy & looking for things to 'audit' for their own PM targets, you don't.
You need:
'Verbal feedback given' stickers, 'Two stars & a wish' for peer assessment, & a couple of smiley face stampers for completed tasks. All of these are applied by the students, not you! Get them to award each other effort grades/merits - they're usually terribly scrupulous.
Make good use of Extended Learning Tasks, & Booklets for homework - cobble one together from TES or Teachit worksheets for each scheme of learning. Generates less marking - it's not sitting there in their books looking like you should've close marked it. Better yet, persuade your HOD to sign up to an online homework site like doddlelearn.
Discreetly build in a 'non-marking heavy' week for each year group, each half term, to stagger things a bit - year 9 might be spending much of a week watching & discussing the film version of their Shakespeare play, so that gives you a breather in which you can catch up with their books in those evenings.
Never waste a lesson in which you aren't actively teaching - so if year 10 are getting on with a controlled assessment or exam practice in timed conditions, use that lesson to 'flick & tick' year 7 (or year 11).
All of this frees up time so that when you do need to spend 8 hours marking one set of top set year 11 essays, the rest of the books are looking respectable & you can set aside the weekend with a clear conscience to do justice to them!
It gets easier
.