Someone asked about how to get the weight even on both feet in Parsvottanasana.
So that you can feel your weight distribution in any standing pose (where both feet are on the floor) first of all practice shifting weight while standing upright with feet about hip width apart. Shift from center to right to center to left to center.
Move slowly and focus on feeling your feet.
By moving to one foot then to both feet you should, from experience, be able to learn to feel when your weight is even on both feet. You can fine tune by noticing the way the front of each foot and heel presses down.
Try to make both equal when standing on both feet with feet symmetrical.
In a pose like Pyramid Pose (Parsvottansana or Reverse Prayer) it may not actually be possible to get the weight even between front and back foot. (And after the above exercise you may be able to feel this.)
But to equalize weight as much as possible, try pushing your hips back. Your hips will tilt as you do this. That's fine. For know notice the pressure change in your feet as you push your hips backwards. Can you get your hips far enough back to make the pressure in both feet even without bending your back knee (and while keeping both feet flat on the floor)?
If you keep your torso upright, you will more than likely be able to get even pressure on both feet without even pushing your hips back. As you bent forwards to horizontal, you'll probably find that you have more weight on your front foot even with your hips pushed back. As your torso drops below horizontal and gets closer to your front leg, you may find that the pressure in both feet becomes a little bit more even.
Forgetting about getting weight even on both feet, my own current preference for this pose is to push forwards through the front leg and using that action to push the pelvis backwards while keeping the pelvis level and square to the front.
Then from there I reach the ribs and head forwards (and down) away from the pelvis. From there I adjust the "feel" of the back leg.
While I might not get equal weight on the back leg, I can get a similar feel between the legs by slightly rotating the rear leg outwards and activating the foot in such a way that the forefoot and heel of the foot press down with similar pressure. Then I end up with both feet feeling similar but with the front foot having more pressure.