Do Heavy Squat walkouts.
Load up 125% of your max squat and walk out with it... stand for no more than 10 seconds, and rack it.
auxillary work utilize the 6-8 rep range:
Back extensions (use plates behind your head or start using a barbell behind your neck)
Work your abs as well, they're super important to your arch.
-Weighted roman chair situps will toast you (hold the plate behind your head, when you can hold a 45 for 10 reps your ab strength is hiiighhh).
-Dragon Flags. If you know how to do them you see the benefit I dont have to go into it.
-Hanging Pikes. Popular gymnast/crossfit exercise, I'm not sure how to make them harder other than increaseing reps, loading them is kind of weird. I'm sure there's a method (if anyone has one, let me know!) I like to do these for reps.
-Ab Wheel. After a warmup I like to do the hard variations (standing to full stretch) then do a bunch of reps with an easier variation (on knees).