I went to come classes once, a mixture of Qui Gong and meditation. I find it ridiculously hard to switch off, even during meditation although it did help me to learn how to focus on something more relaxing.
I was just sat comfortable, no ommmming or anything like that, just relaxed and learning to feel grounded and focus on relaxing things like my breathing or a relaxing vision.
I find it helps with stressful situations and getting relaxed to sleep and with a medical condition.
I can now do thngs like focus on my breathing and the tip of my nose to help calm myself and focus, I can help relax myself for sleep by imagining each part of my body relaxing bit by bit in waves and when I have the onset of dizziness/vertigo (clinical from ear disorder) I can help myself feel more grounded (feet flat on the floor and feeling attached, if that makes sense, breathing etc...) and focus.
I was also taught a technique to destress where to take a deep breath in through your mouth then hold and release slowly through your nose and another where you take a deep breath and slowly breath out then, when done, make a final exerted breath out. The latter one tends to make me laugh but that is good in itself :)