Low Lunge Tip
One of the most common adjustments I recommend in yoga classes is for the Low Lunge. This is a reasonably easy pose but many people don't start with their leading foot far enough forward. I usually recommend people take a little step after they bring that front foot forward, that way the shin ends up perpendicular once you lunge forward.
This pose is great to gain a deep stretch for the hip flexor on the rear leg.