Eat with your right hand, even when using bread to scoop shared food. Offer and accept things (money, business cards, food, a handshake) with your right hand, or both hands for something formal.
If your right hand is occupied or unavailable, it’s fine to briefly explain rather than use your left hand by default.
The same “lowest, cleanest last” logic applies to your feet: don’t point them at anyone, rest them on furniture, or cross your legs in a way that shows the sole of your shoe to someone across from you, especially in a mosque or someone’s home.