| The above suggestions are great. As far as technique goes, my opinion is that the only purely bad technique is one that is bad for the health of your hands but some may disagree. I've seen players whose technique I think is sloppy but that doesn't mean that it's bad. The first bad habit I would try to look out for is really severe and unnatural wrist angles in either wrist. This can cause a lot of problems down the road. I learned the hard way with really bad pain. Thankfully, I was able to correct it before I did any permanent damage. A slight curvature is ok but you definately don't want your wrist making a 90 degree angle. Wear your bass at the right height so that you can play with more natural angles. The other thing you should try to avoid is over extending. For instance, if your playing an F note on the 1st fret E string and the next note is G# on the 4th fret on the same string, move your hand up the neck instead of trying to stretch all the way to that note. Unless you have a ridiculously wide span trying to stretch that far is going to put your wrist at a very sharp angle.
With all that being said, Jimmy's right about finding a good teacher who can really teach you safe, fluid technique. | 
