One quick way to improve your strength and to get that "one last rep" is to remember to grip the bar, the dumbbell, the kettlebell, whatever your tool may be, as hard as you possibly can.
The cue I use is to "leave your fingerprints on the handle." Grab it like you're trying to squeeze dents into the bar. If the grip is soft (a padded pullup bar, or add-on bar thickening grips), even better - leave visible dents in the material with your grip.
This squeezing will automatically generate tension down your arms and into the surrounding muscles. It's hard to grip something hard without gain tension elsewhere. This extra stiffness will make it easier to transmit force from the muscles moving the weight to the weight itself.
Try it and see!
2 hours ago