How to keep stranding always in the back side? And, am I supposed to use certain type of stitch per row when fair isle knitting?
The RS (public side) you knit stitch - the WS (with all the floats) you purl stitch.
When doing the float side have all your yarns dropping in front of the work (where you had them dropping behind the work when doing the public side).
Here is a vid which might you help see what you need to do with fair isle.