The 1-2-3 combo of Rocket Grab, Power Fist, and Static Field can devastate an individual opponent.
Using Blitzcrank's grab to pull an enemy into your tower range followed by a Power Fist will allow the tower to get several hits on them.
Blitzcrank's passive Mana Barrier grants him a shield when he is low on health.
Staying behind creeps can prevent you from being Rocket Grabbed. Blitzcrank's Rocket Grab only pulls the first enemy target it encounters.