It's possible and necessary to use the same inspiration to create different knit outcomes. By using different techniques and yarns you can end up with a completely alternate swatch or ones that can sit together within a range.
Over the next few weeks we'll look at different outcomes from the same inspiration. Like this one, which the inspiration of, has been posted before.
Textile inspiration can start with anything really. But normally, for me, it begins with either an illustration, croquis (which is a small test pattern) or photo. Illustrations, especially fashion ones give a lot more information than the other options. This can be really helpful in deciding things like fibre, density of the fabric, and even how much detail may or may not be added. Like any form of design outcome (and probably like most things in life?) the more you know, the better off you are.