Last week I posted an example of a poorly constructed entry to handstand. I asked YOU what was wrong, and specifically, where the problem started.
I got a lot of great answers, including observations about inadequate core engagement, arched spine, hand position, and shoulder alignment.
Now, depending on how you think about it, you could say the problem originated in a variety of places. So keep in mind my answer is not necessarily the end all be all.
What I was trying to show in this example was how shoulder alignment can cause problems in the entry and the entire handstand shape.
In this example, my shoulders fall behind my wrists or barely stack over them. This is a common mistake that causes the torso to fail to stack.
Solution: Shift your weight forward MORE. Let your shoulders shift over, but not past your fingers. Once you stack, your shoulders will naturally shift to be over your wrists.
If you try to kick up with your shoulders too far back, e.g., if you never shifted them forward from the position in the first image, you will HAVE to arch to get your hips over your shoulders, and your shoulders will be closed.
In the video, the other really serious issue is that there is no hollowing of the chest. You want to be pull your ribs in by expanding your upper back as you approach your entry. Think of the "cat" position when you are on hands, knees, and feet: back is rounding and pushing toward the sky.
To learn the most common handstand mistakes and how to avoid them, purchase the How NOT to Handstand Ebook.