How you hold and support your bass guitar is very important and should not be over-looked. Poorly holding your bass will negatively influence all other bass technique.
Strap In
You should use a guitar strap 100% of the time when you play your bass. The strap is an essential part of your bass technique. Your strap should hold your bass for you. Your hands shouldn’t be doing any of the bass holding or balancing. Your hands need to be free to play. I can't emphasize enough that you should always be using a strap!
Purchase a very comfortable strap. You, your back and your shoulders will be glad you did.
Bass Height
The strap should comfortably hold your bass somewhere above your hips and below your collarbone. Most people have it belly button level. Everyone is a bit different. Experiment.
Try to adjust your bass so that it sits at the same height whether you are sitting or standing. If you sit while practicing and stand while playing, this will help you play just like you practice. Being consistent is a big part of learning to play bass well.
The Cool Factor
You will see a lot of people letting the bass hang around their ankles thinking it looks cool. Don't. It doesn’t look that cool and you will cause yourself many back problems, technique problems and hand injuries. Eventually people will think it’s cool how well you play bass.
Posture
Your mother was right — sit or stand up straight. You shouldn't be leaning back in a chair or hunching over as you play.
Angle of the Bass Guitar
Hold your bass guitar at about a 30-degree angle. You will notice if you hold the bass perfectly level your plucking hand/arm is forced upwards while your fretting hand/arm is forced to reach down and around more and at a bad angle. This can cause a lot of posture problems and forces you to bend your wrists more. Sharply bent wrists lead to carpal tunnel syndrome. By angling the bass guitar you help straighten out your wrists, straightening your back, and leveling your shoulders.
Don't underestimate the importance of how you hold the bass guitar.
