I’ve been lifting for about a year and a half. I have been very cautious with deads to avoid injury.
Regarding the three basic lifts: deads, squats, and bench- dead lifts need the most improvement.
What supplemental exercises can you recommend to safely increase the weight?
To safely improve your deadlift, train your posterior chain and your grip!
Posterior chain lifts:
45-degree hyperextensions
reverse hypers
glute-ham raises (if you aren’t strong enough at first, start with isometric holds in various positions)
Low-cable pullthroughs
sled-dragging
box squatting
Grip training:
Heavy dumbell holds or thick bar holds
Captains of Crush grippers
pinch gripping plates
wrist roller
Titans Telegraph from Ironmind
hammer curls