Overloading or 'walkouts'
Load up the bar at 120% of max and static hold at the lockout position on bench or with the bar on your back for squats. Hold for 15 seconds.
This will increase the amount of connective tissue you have.
You can also do plyometric or explosive lifting. Box squats for instance. Also kettle bells. You're only lifting about 60% of your normal weight but doing it 2-3 times as fast. Your muscle contracts at high force shocking tendons and other connective tissue. They handle the stress by becoming denser.