Back stitch is a great line stitch for outlining. Vary the thread thickness for changing effects. It’s a simple stitch that has a wide range of uses.
Bring up the needle just a small amount in from the beginning of the line. Make the first stitch by bringing the needle down at the start of the line.
Bring the needle up again one stitch length away from the first stitch.
Bring the needle down at the end of the previous stitch. Continue this to the end of the line of stitching.