Me personally, I like the box method. Most of the times you hear about the triangle method. 3 second breath in, hold for three seconds, breathe out for three seconds, repeat. I never found that to be natural. Eventually I learned to hold after the down breath as well. Also the specific amount of time to hold doesn’t matter so long as it’s nice and rhythmic. Eight counts are nice.
In order to do that comfortably you need to learn how to breathe properly. Fill your belly first then your lungs. When I was coaching people we would start with deep rhythmic breathing to get the mind in the mood for growth. It’s a highly underrated technique, you literally can’t go wrong by working on your breathing.
if you’re trying to meditate, then be mindful of hyperventilating. it’s not harmful but it will interfere with trance induction. This is one more reason to work on deep breathing, your body and mind should be acclimated to a vastly increased oxygen intake. And when you finally cross that boundary and find proficiency in meditation, being able to more precisely control your level of energy is hugely helpful for things like OBE.