Good
tinker - To attempt to repair or improve something in a casual way, often to no useful effect

Mitch tried to tinker with his computer before realizing that it was more broken that he had thought, and that he had to bring it to the computer store to have a professional repair it.
regimented - Referring to something that is arranged in a highly structured or ordered manner, often with little room for flexibility or deviation.

He was determined to lose weight, and he realized that he could accomplish this only with a regimented approach to exercize and diet.