OK, first caveat - I am not, never have been, bever will be a teacher - this is purely how it worked for me - I started off with 5 string concentrating on the fifth position and working on simple stuff like walking bass lines until comfortable effectively transposing stuff. From there I found it fairly straight forward moving down the neck, although I must admit, using open position did take a while longer.
This may stem from the fact that I am not very happy playing in the open position in the first place having spent many years as a rhythm guitarist in a Big Band so playing a lot in Bb, Ab and Eb.