usually i just have to rely on my intuition. like that doesn’t look right. or i don’t think that’s proportional. i sometimes do check with the head rule and adjusting whatever’s closer is larger and whatever is farther away is smaller and see if it still fits the rule. tbh i would just practice redrawing images with more extreme perspectives to get used it. also redrawing the space in perspective with just like guiding lines. breaking things down geometrically definitely is good for perspective pieces. think about the shape rather than what your actually drawing. like a leg is a few rectangles and circles rather than a leg.