Hi B.! A friend of mine bought me a book for my baby shower called Baby Gami. You can find it at http://www.amazon.com/Baby-Gami-Beginners-Andrea-Cornell-...
The first half of the book shows swaddling techniques - and the little differences in the fold of the blanket make all the difference in how tight and how long the swaddle holds. They also show how to wrap a sling around yourself. I tried as many baby carriers as I could find with my daughter, and I always go back to using the sling I made. Every time I am out in public with the sling on, I get stopped and asked where I bought it. It takes a length of fabric between 3 and 4 yards depending on your body type. I have some heavier weight fabric for the winter, and lighter weight for the summer (it is actually lace I use for the summer). Any fabric with a slight stretch will work - and no sewing is needed unless you absolutely want to sew the ends over.
Basically, you start with the middle of the fabric, put it across your waist and to the back. Then you cross the ends in the back, and put the ends over your shoulders so you have an X on your back. Next, you cross them in the front, then pull the ends to your back and tie in a knot. You have an X in the front, and an X in the back.
You can wear the baby either in front, or in back. To put baby in, you put their legs through the top part of the X, then through the band around your waist. You can pull the waist band up all of the way to their shoulders to support them while they are sleeping. Make sure that you wear them above your waist for your own comfort. I am only 5'3" tall, so it is possible for shorter people to do this as well!
Good Luck and happy baby wearing!