on one hand
1. From one particular point of view. (Typically followed by "on the other (hand)," highlighting a second, conflicting point of view.) I'm really torn. On one hand, I'd be starting a high-paying job doing what I've always wanted for a living. But on the other hand, I'd have to move halfway around the world from all my friends and family to do it.
2. Indicating a very small number. He's the stingiest guy I know. I could count the number of times he's offered to pay for something on one hand.