This is fun! I like doing it. It takes a bit of time, but its worth it.
Take two pieces of fabric larger than what you need. Place them right sides together. Trace onto the back of one of them, the pattern you want. I've done two................a heart and a leaf. I also used a pigma pen so you can see what I'm doing................I DON'T RECOMMEND DOING THIS. Use a marking pencil...your choice.
With the two pieces of fabric right sides together, stitch ON THE LINE all the way around. You can backstitch when you get to the end.
Trim (I used pinking sheers so it will not fray) very closely to the stitching, but do not cut the stitches. Go slowly and carefully. You don't want to have to do it over especially if you are doing a lot of them.
Pull the two pieces apart and carefully make a slit into the middle of one of them. Make sure you are only cutting the one piece.Turn them right sides out.
I use my bone folder to give it a nice smooth edge and then take to the iron and give it a good zap of steam. You can use a chopstick if you want too. They do the job nicely.Stitch around the edge using a straight stitch. Its up to you where. I sew about 1/4" inside the edge.
For the leaf, I stitched it so that it looked like the veins.
I just used my regular foot on my machine. If you were making a quilted piece you could use your free motion foot and quilt it at the same time.I know what you want to know. Did I stitch up the slit in the back? No I didn't. My stitching from the front will be enough to keep it closed and secure.
Good luck.