Firstly, focus on lifting all weights free-hand, without STRAPS.

A good way to increase your grip strength and endurance ability to is hang from a pull-up bar for as long as you can.

Deadlifts in particular require strong grip strength, so the more you deadlift and the heavier the weight, the better your grip strength will become.

Performing Wrist-isolation exercises will also increase grip strength, as will drop sets and supersets which will BURN your forearms.

Related Questions:

1. Should I use straps when powerlifting.