It's a two step thing.
One, with the needle down lift your foot and adjust your stitch length, by raising your foot to actually where you want it. Then, on the next stitch, with the needle down, on the next stitch raise your foot then turn the material, Stitch once, twice, whaterver.
where you want it. Raise your foot and turn you material to you new line and sew on!
If not clear keep asking.!
Kevin