When I did the 7 day silent retreat at Vipassana I regret using my valuable time to do what they told me to do.
They teach you to do this very specific thing with your focus. It was about feeling each part of your body. Scan every single microscopic parts of your body. I don't think it's bad, but I feel like I never managed to reach anything special with this.
I think I should've meditate how I wanted to. Just relax and accept to live this moment. Every single moment without trying to do anything but accept and live each moment.