I love using my kids for weights. Linear progression max.
Encounter problems when you can't make a set. You can't roll back 10% and go again. You gotta wait another 9 months.
I bought cheap weights from tip shop. I got no stands, so for squats I am limited to what I can powerclean and front squat. I did start with a 2 metre section of 4" PVC pipe. Fill that with water or sand and do squats, thrusters, overhead squats, split squats. Ghetto cheap until you can save up for what you need. Everything else is just excuses.
Gymnasts do single leg squats, use weight vests and do deck squats and that gives them enough power to do amazing gynmastic feats, but you notice how their upper bodies and arms dominate their legs.