Improving grip strength.
Anyone that's ever worked out with me knows that I'm a stickler for form. I hate seeing a guy make his back look like a cursive N while he tries to deadlift 255lbs (picture me air quoting deadlift). Even more, I hate seeing him do that with straps on his wrists. If you're not going to deadlift the weight properly, the very least you can do is make sure you can hold on to it without help. Now in my opinion, holding the weight without assistance will ultimately help your grip strength develop; patience is the key here. However, for those looking for something extra, I've always had good luck with a simple dead hang from the pullup bar.
At the end of your next workout, try hanging from a straight pullup bar. Try hanging at first for 30 second sets at 5 sets. Once 30 seconds is easy, try 40, then 50, then 60 and so on. Make this part of your normal routine and I think the results will surprise you.