I have long neglected my overcast foot. It gives a "serged" finish to seams without using a serger. The stitch on my new machine actually does a double straight stitch and overcasts the ends while my old Brother overcast stitch was just a single stitch and then overcast the ends. I am probably the last person to figure this out but I'll put it out there in case anyone else has been neglecting their overcast foot too.
While messing around with the tension on my thin cotton camp shirt arm holes, I realized that turning the tension to the highest setting while making the width and length smaller proportionally created an amazing effect. It actually flipped the raw edge toward the seam as it overcast it. This means I have a "hemmed" and serged finish on my armpits. No one likes a frayed armpit hole ticketing them. I wish I had figured this out before i got within 6 inches of finishing the last sleeve. I haven't obviously tried it on different fabrics but I think it will have a similar effect. The only trick I found in getting to flip was to push the raw edge up like in doing a narrow hem rather than flush with the foot. It may end up creating a shell stitch instead of neatly flipping the edge over.
If anyone tries this please let me know how it worked out. I'm curious to know what else this awesome little foot can do!