The ability to pick up a ground ball is just as important as throwing, catching, and cradling. Ground balls means more possession for your team. Everything else becomes irrelevant if your team can not get a ground ball. Your effort on ground balls will show that you are doing whatever it takes to win games.
Before there is effort there are strong fundamentals. Form is very important, a few simple things can allow you to snatch up GBs from players that do not use popper technique.
Scoop through the ball, and bring the stick up towards your chest without trapping the ball. All the while, you should be moving your feet and rolling away from defenders who will be looking to throw hard checks immediately after you pick the ball up.
Spread out your hands on the stick.