Today I managed to get in 7 miles of walking at the gym along with a killer arm and back workout, which included 20 sets of neutral grip pull ups. One of the things I've been working on is hand position while doing a pull up.
Please note: When you do a pull up, you're not going to hang from your fingers. You're going to put your hand completely around the bar and then rotate the hand down slightly. Now the bar is in that area of your hand that allows the greatest amount of surface contact with the bar. Keep your wrist slightly upwards rotated in order to keep your skin less pinched on the bar. Always try to use a bar that's not too thick or you won't be able to properly grab around the bar. The thicker the bar, the more demanding the pull up. The same is true if the bar is too thin. A thin bar gives you very little contact surface. So if you have several options, try the bar that offers you the best grip and the best ratio for your hand so that you can grab around it with a good surface contact.
Have a wonderful day!