Tenant won't pay security deposit despite damages

[Tim Lin]

Hi everyone,

A tenant is moving out and I noticed some damages such as dented/chipped door frame, possibly happened when he moved his furnitures in. I brought this up and he casually brushed it off saying something along the lines of "it was already there, he never notices it, it's not much to fix." He'll be moving out within the next few days and I'll do a full inspection then. I'm a fairly new landlord and next time I'm thinking of including a video and/or photos of the room's condition to the contract.

My questions are:

1) What's a good way to handle this as a landlord if he ends up refusing to pay for damages? Hopefully there's no more.

2) What are some precautionary steps you take to avoid dispute, ambiguity (he said, she said) or situations like this? 

Thank you,

Tm