Even if you’ve only been playing bass for a couple of months, you’ve already developed some playing habits. If you’ve developed some bad ones, here’s what I recommend to help fix them:
Stick to the Unfamiliar
Take a break from playing anything you may have already learned to play on your bass. If you play things you are familiar with, you will quickly jump back into your old bass playing techniques. It will be easier to adapt new techniques to new, unfamiliar exercises, basslines and patterns. Once you’ve gotten better with the new bass techniques, it will be easier to go back and apply them to the music you were playing before.
Avoiding songs you often play can be difficult if you currently play in a band. You will have to make an extra effort to work on your band’s songs applying the new techniques you want to develop.
If you’ve been playing for a while, you’ve built up some facility to play things quickly. You need to slow things down and pay attention to what your hands are doing. The faster you go, the more likely you will jump back into your old habits and make mistakes. Pace yourself with a metronome. There's no shame in working at things slowly.
Watch yourself in a mirror. Point the neck of the bass at the mirror so you can see the reflection of your plucking hand and, at the same time, you can see your fretting hand. If you want more feedback try recording yourself with a video camera. That can be very eye opening!
Overall, just be patient with yourself. Always try to learn things correctly as soon as possible. The more you delay, the harder it will be to change later.