it's all in how you set the rotation. if you set it poorly, and have to really focus on making the spin around by twisting your body n shit, a grab will never work. if you set it hard and let it follow thru, you can focus on the grab.
but more importantly, practice. get confortable spinning first )and doing so without having to turn your head to look for the landing, which results on twisting your body). if you can carry a 3 around effortlessly, dialing the landing every time, grabs will be easy to throw in.