One of the things I've been checking lately is the quality of movement of the posterior calcaneus. Passively where does it lay when the patient is prone. Is it stuck in a big inversion or does it appear to be somewhat neutral? It starts to help when you see someone a few times and recognize what is their normal and when they have any lower limb issues and the calcaneus is in a different position.
I first started paying more attention when a Strength Coach that studied under Gary Gray talked about the need of the calcaneus to evert in order to get maximum strength out of the Glute Max.
Outside of adjusting the calcaneus, I've really been going through the ligaments and feeling for the ability of the calcaneus to move against the distal fibular head. I've noticed when this improves the tone of the calf often changes from having some tension to more of a relaxed state. Whether this is just reflexive change or worthwhile, it's hard to say. But, all joints should have good movement.
I've usually found tension in the calcaneofibular and post. talofibular ligament. Generally speaking, working the connective tissue on the backside of the heel/fibula where I find tension. Give it a try if you have a patent with consistent calf tension or foot biomechanics seem off. Every joint should have quality motion.