Most sports require good grip strength. And if you like lifting heavy barbells off the floor, grip strength is a must. This odd-looking but effective exercise builds dynamic crushing grip strength. It's also a great movement for forearm size.
Simply pick up a bar with a double overhand grip and pull the bar up as high as needed for you to catch it with a double underhand grip. This is a great way to get in extra grip work without any special equipment.
I like to include grip training at the end of my lower body sessions, after deadlifting. You're welcome to include grip training on other days if you find that works better.