It is astounding to see so many pool enthusiasts and freaks who pay little attention to the solidity of their bridge. It is not only necessary to design a solid and functioning bridge, you must also keep it there throughout the execution of your stroke.
The weight of your arm should be sufficient enough to plant your hand onto the table, so that it digs in nice and snug. However, you do not want so much weight on your bridge hand that if it were to move, you would fall on your face. I like to plant my palm as well as my pinkie, ring, and middle finger onto the table. This gives me stabilization, increased feel for the cloth, and brings me down to the level of the balls. Sometimes I lift my palm and support my bridge solely with my fingers. This is helpful for follow shots so I don't have to squeeze my hand to elevate the cue. It is also comfortable because my hand is in line with the forearm, creating a very stealthy and sleek approach.
It is ideal to have your fingers conform to the shape of the shaft within your closed bridge. This will ensure that your cue will not drastically deflect off the cue ball and/or miscue. This is especially important on draw shots. Make sure you do not squeeze the cue so much that the friction hinders your smooth stroke.
Your bridge should be finalized simultaneously with your stance, so you can now focus on your strokes. DO NOT EVEN SLIGHTLY MOVE ANY PART OF YOUR BRIDGE HAD UNTIL THE END OF YOUR ACTUAL STROKE! MAKE YOUR BRIDGE LIKE A ROCK!

