A few notes on designing a good warm-up
First rule: NEVER, NEVER practice handstands without warming up your wrists first.
I recommend a minimum of 10 full minutes dedicated to the wrists only, at the beginning of the session, as well as a softer routine of massage and mobilization of 5 minutes at the end of the session.
Personally, I had to increase the volume up to at least 15 minutes a day to properly prepare my wrists for an almost daily practice in my early days. Many professionals today bitterly regret not having taken the time to do this. Learn from their mistakes and don't imitate them
Second rule: don't confuse warm-ups with joint preparation.
Doing hand circles for 5 minutes is a warm-up. Working on wrist mobility and the strength of hand and forearm muscles for 10 - 25 minutes is a prehab session. You need both.
UY a first routine to know what to do and how to do it when you warm up and prehab at the beginning of your training session.
Soreness 🤕
If you tend to experience serious soreness in the wrists in your practice - don't worry. You will get used to the demands of handbalancing in a matter of week.
If that happens, make sure to take a step back in terms of volume.
The prehab is be performed on rest days, without any attempt at handbalancing, if you experience soreness.
As I say in workshops - just do it when you watch Netflix, or when the kettle boils.
Do it, as you are performing something static during your day, so that it doesn't become a chore, but just something you do at the same time as a daily task.
It's one of the easiest ways for you to make sure you won't forget it.
Warm-up routine #1
For any warm-up, 10 reps / 30 seconds for tension drills is a good start.
Spend more time on the drills that you feel your body needs.
For shoulder health and mobility, you can add the following exercises, twice a week:

Shoulder flexion with stick x 10

Suspension x 20 - 40s
If you don't have a pull up bar at home - worry not. These are a nice plus, not a must.

I will give you many more drills in the following modules. Meanwhile, use those videos as examples to inspire yourself from to design your perfect warm-up routine.