This video shows how I straighten bent tube pins. Try to be careful when you insert your tube into a tube socket. If you look at the socket, you will notice an blank space (no hole). Align your tube accordingly.
Never force, but sometimes takes a little pressure to get the tube inserted. You always want a tight secure fit.
When a tube socket goes bad or wears out, it will need replacing. Usually this happens on older amps.
On the larger output tubes and rectifier tubes to maintain a tight grip on the tubes, sometimes all that is needed is to tighten the socket hole metal by placing a small screwdriver between the socket and the metal and bending. THIS IS DONE AFTER THE POWER SUPPLY HAS BEEN DRAINED OF ALL CURRENT. IF YOU DON'T KNOW HOW TO DO THIS, THEN DO NOT ATTEMPT THIS PROCEDURE.
You want to keep a snug fit by the socket on the tubes at all times. Noise is sometimes generated it one pin does not have a tight fit with the socket. You can eyeball the socket clamps to make sure all look similar. Sometimes noise can be generated by a loose wire attached to the socket.