I know you don't want to hear it, but it just takes practice...
I find it easiest to pull downward at an angle for pull offs. It's kind of like opening a door almost. Grabbing the knob with my palm facing upward then turning it clockwise. My motions aren't really that exaggerated, but I get a "down and to the left" angle going when I perform pull offs.
My only advice for hammer ons is to make sure you keep your fingers near the fretboard while playing. You'll find that your pinky wants to fly away after it does its duty and it's going to the next string. Focus on economy of motion, then work on endurance and speed... practice practice practice practice practice.
"You must stab him in the heart with the Bone Saber of Zumacalis... well, you could stab him in the head or the lungs, too... and the saber, it probably doesn't have to be bone, just anything sharp lying around the house... you could poke him with a pillow and kill him."
- Aqua Teen Hunger Force, The Universal Re-Monster