In SFQ I have heard that to have your palms up for normal practice- unless you have high blood pressure then have your palms facing down (rest them on your knee caps).
I would suggest 'small universe' to help balance the energy in the whole body. Breathing in this way is known to have many benefits and over time should correct most all physical problems.
Holding your breathe really isn't advised until you have become fairly advanced. Some reasons not to, include that it messes up your body's natural breathing, it adds tension to the body which shows up as misemotion, etc.
Just breathe.
