Starting with 1st and 2nd fingers, pick a comfortable spot anywhere along the neck, on the bottom 'E' string. The notes are to be played as if you are climbing up from string to string with two fingers, so bear this in mind: when you climb a ladder you must always have at least one foot down or you fall off! *Watch it here*
So how you achieve a fluid change of notes is the same way as steady climbing up ladders: a finger goes down, then the previous finger rises, you always have contact with one of the strings or you lose the run of the notes.
Last key point: when you put each finger down, don't let it drift into place, do it like you mean it.

Consider that now with 4 fingers: the 1st finger presses its note, the next 3 fingers press their notes one-by-one. If all 4 fingers are still down on the string and you want to move up to the next string, you have a big problem- they will all have to lift off, reposition and start again which leaves a huge gap of unskilled silence in between.
This is the skill to practice:
**Watch it here** Finger 1 on the left presses it's note and stays until 2 takes over the string, from that point 1 has finished it's job and can start moving to the next string while the rest of the fingers carry on the wave in the same motion- next one down / last one up.
This way when you want to change strings the 1st finger is ready to go with no break in the flow. It also makes it easier to reach your last finger to its furthest fret because it is not being held back by 3 others, it is rolled into place.
This should be practiced with three, then four fingers, in both directions and once you master it you will dance all over many songs including Come As You Are, Roadhouse Blues and Woo-Hoo.
Last key point: when you put each finger down, don't let it drift into place, do it like you mean it.
