Not sure I know exactly what you mean. It is correct that if you want to go up or down in pitch you do so by a whole/half step on one string. Ideally, your fingers should be parallel with the frets, with your thumb behind the neck, in line with the middle and ring fingers.
No rules are written in stone, if something works for you, that's fine, however, there is a tried and trusted technique for the left hand. This allows you to get the best out of your playing, and also helps to prevent physical injury (carpel tunnell) at a later stage. Below is a link that shows good L/H technique.
http://www.adamnitti.com/bass_player_03.shtml
For R/H technique you could also search You Tube for "Floating Thumb" technique by Todd Johnson.