Increasing grip strength

[h21]

Hey guys I have really small hands and because of this it's just hard to get past 4pl8 deadlift without the bar slipping through my hands after 1 rep. I don't use straps/chalk and don't want to (maybe I will for higher weights when I get there); what are some good exercises/activities that will help improve my grip strength?

 

I've noticed the weaker parts of my grip strength lies on my ring and pinky finger, like when I grip the bar I usually put most of my strength on the index and middle finger.