Hands
How do I hold my hands while meditating?
There are no real solid rules except 1.
You left hand represents "earth" energy and your right hand represents "sky" energy. This is because in the natural order, the sky is above the earth.
The right hand should always cover the left hand.
You can meditate with open or flat hands, facing either up or down.
You can rest your hands on your legs, or chair.
When you get to advanced stages of meditation, then your body will align itself with the correct posture.
Joining Hands
Not recommended.
Here is the "trick". When you meditate with people you do not know, then you do not want to absorb any of their negative energy (especially directly by body transference).
Then there is also the issue with some people being "inappropriate" when they touch others. This will ruin a meditation session almost immediately for everyone. Especially the victim.
However
Let me share a middle way to do this and no one gets offended.
If you truly want to connect with people while meditating, try opening your heart with love for all of those around you.
This is an amazing technique and extremely powerful so you may become very emotional - and so may the recipients of your projected energies.
You will feel a massive and powerful light emanating from your chest (heart).
When you get good at doing this, you can actually project this energy to the group.
Couples
If you are doing this technique with your partner, and you truly love them, then this will literally blow your mind.
BTW: It only takes one person to initiate this - but when it is reciprocated, then the energy and feelings are not of this world.
Caveat You may end up crying.