In posture, the core is to keep the spine straight. Cross-legged, it doesn't matter whether you like it or not; Hands can be crossed or naturally placed on your knees. It doesn't matter.
By the way, the spine is straight, just keep it roughly straight, and don't exaggerate it. Especially the waist, don't bend over, and don't deliberately straighten your waist, like the S-shaped curve in women's weight loss advertisements, which will be counterproductive.
On the basis of keeping the spine straight, you can choose two postures. One is sitting posture and the other is sleeping posture-yes, you can meditate when you are asleep!
The orthodox practice is to sit cross-legged But first of all, many people can't get up cross-legged, and their bones and muscles are too hard ... So as a simplified version, you can sit on the chair with your feet on the ground, and ordinary sitting exercises can do the same. The effect will not be weakened too much, and the improvement of the brain still exists. Day students recommend this practice. Of course, if you are flexible, orthodox cross-legged practice is better.
Some students need to prepare some tools. The most important thing is earplugs, because meditation needs to be quiet and there can be no sound interruption. It is difficult for students living in dormitories to have a quiet environment. When you sleep, you are concentrating on your practice. When others get up to go to the toilet or even turn over, the bed creaks, which will interrupt you and seriously reduce the training effect.