I recommend looking at a YouTube channel called yoga with adrien. She is amazing. Look for anxiety and stress under her channel. I would also try one of her 21 day challenges. I love her her yoga is relaxing. She makes you feel comfortable.
I find basically any sort of stretch helps, as long as i give it my full attention and keep aroutine for at least 3 minutes. Anso i try to go to a "safe place" when i do that; generally outside and somewhere green. But just getting outside the building helps. Then i guess it comes down to what makes you feel great. Personally i love to reach for the sky, stretch upwards, hands as high as i can, and take deep breaths. Then bring down my hands in a circle, or clenched fists like dragging something down. I think it's the concentration on my body and breath and feeling my power and my lungs full that helps calm me down. Then after i did my routine i bask in that feeling of fullness for a few minutes. Just take it in. Feel strong and alive abd free, no pressure, for a few minutes before going back to whatever you were doing. I set up a "power pause" to do this every day before and after lunch at least, and also at 4pm.
The best stretches are the patient, and thoughtful ones. Stretching best when you stay with the movement mentally. Meaning, be present through every breathe and feeling. If you feel any discomfort or resistance, stick with it and don’t push it away. Notice it, as well as your body. 8 seconds is a good minimum to hold a pose. All stretches/poses are good for anxiety in my mind. Specifixally poses/stretches where the abdomin is engaged is very good as a lot of anxiety is experienced in the stomach region. “My stomach is in knots because of the interview”… “I feel sick to my stomach about the news”…
I think any gentle stretches that feel good would help with anxiety. Anxiety can make the body feel tense and stretching is a positive action and one that can help the body relax!