Ham fisted as in, a very fat persons hand. Lacking dexterity, and producing poor results in tasks requiring accuracy. Makes sense as the phrase is used to describe something done clumsily, poorly executed. The saying is not limited to physical actions, it can also apply to social situations, a versatile phrase, and/or insult.
"Luke locked himself out while drunk last night and ham fisted his way into the house by kicking inthe fucking door. He's a liability, I swear."
"John's game is so cringey, man. He just sent out a mass text on tinder saying he can speak french and make girls squirt. Like he thinks that will sway a girl who's on the fence his way. Ham fisted bastard."
Receiving total hand pleasure from a large handed sweaty man who may or may not have recently eaten a large quantity of meat; hence giving him the meat sweats causing a "ham like" scent.
Someone who drives with the fingers of one hand gripped into a fist at the 12 o' clock position of the steering wheel of any vehicle.
These types of drivers are well known for thier cockyness, tailgating, speeding, reckless lane changing, having their seat reclined to a 140 degree angle, not using turn signals, and complete disregard to other motorists.