This is my first attempt at intarsia, and I used duplicate stitch for some of the smaller color-changes. The intarsia portion is worked flat, and then the fair isle border is added in the round by picking up stitches. I also embroidered some flowers, then backed it with fleece.
I’m sure someone with more experience could do a nicer job keeping the edges straight and stuff, but the pattern took forever to make, and I wanted others to be able to use it if they want!