Though there are other coaches and athletes who emphasize grip strength, Jedd Johnson was the first one that got my interest in it about ten years ago.
A weak grip is like no grip at all!
Think of how many things in your daily life that require grip strength. Even something as basic as a good, solid hand shake (which is quickly disappearing from America) is based on grip strength.
In lifting, grip strength is 100% solid gold! You must have strong hands, wrists, and forearms!
Here's part of my grip training.
I got the steel grip balls from Ryan Pitts and the Eagle Loops from Iron Mind.
I also use sandbags for grip training, which I learned from Zach Even-Esh.
There are numerous way to train grip, just pick one or two and get started!
The Cave 