I'm doing the startbodyweight.com routine. In the squat progression I find everything up to and including deep squats, close squats and beginner shrimp squats easy and I can do 20 of them without too much trouble.
Assisted one legged squats is a huge jump and I find them basically impossible to on the left leg with anything approaching good form (video). The right leg (video) is better, but I still require quite a lot of pulling on a door handle to get back up. I can't do what looks like delicate balancing with fingertips I've seen in youtube videos.
Is there something else I can do to improve my leg strength (particularly the left) so I can get to doing assisted squats?