If you're going to run outdoors, please, don't run barefoot.

• Your joints will thank you (less impact on the joints).
• You've avoid dangerous objects on the ground (broken bottles, glasses, etc.)
• Without safety worries on your mind, you can focus on doing what you love to do: running.
• And other reasons I cannot currently think of.

If you're running indoors, it's still safer to run with some shoes.

That being said, this source details how to improve your running, barefooted or not. The highlights are simply:

• Your Stride: Covering more distance with each stride is optimal.
• Your Footstrike: Landing on your forefoot is better for your performance, but it might be hard on your calves.
• Your Posture: Looking ahead of you and not on the ground is optimal.
• Your Arm Posture: Less arms swing is optimal.
• Your Bounce: Reduce your bounce between each stride to reduce the energy expended and to conserve your energy.

Hopefully, these tips help.

Keep running :).

If you're going to run outdoors, please, don't run barefoot.

• Your joints will thank you (less impact on the joints).
• You've avoid dangerous objects on the ground (broken bottles, glasses, etc.) wearing minimalist shoes can reduce/solve this problem.
• Without safety worries on your mind, you can focus on doing what you love to do: running.
• And other reasons I cannot currently think of.

If you're running indoors, it's still safer to run with some shoes.

That being said, this source details how to improve your running, barefooted or not. The highlights are simply:

• Your Stride: Covering more distance with each stride is optimal.
• Your Footstrike: Landing on your forefoot is better for your performance, but it might be hard on your calves.
• Your Posture: Looking ahead of you and not on the ground is optimal.
• Your Arm Posture: Less arms swing is optimal.
• Your Bounce: Reduce your bounce between each stride to reduce the energy expended and to conserve your energy.

Update

This, this, and this are just three resources out of many that are showing that barefooted running can indeed cause injuries. And frankly, anyone who has run with and without shoes knows that there's a difference on the pressure on joints (especially on hard surfaces). The trick to reducing the pressure on joints take time and practise to master.

Hopefully, these tips help.

Keep running :).