I cut strips on the bias, a little more than twice as wide as I want the vine. I fold it in half, with right sides facing out, and make a seam close to the edge. only when that is done, I iron it, positioning the seam in the middle of the backside, where it won't be showing.
Steam a seam makes tapes in 1/4" and 1/2" wide that work great to hold them in place (and stick in leaves) until you sew down for good.
One of the reasons applique is so popular is that there are so many ways to do it, so you can take your choice.