I just went around the neck and arm holes with the zigzag stitch.
Mk, tutorial time. lol.
I started out with 2 ringer tees.. but I suppse it would work with any kind of tee.
Shirt one will be the end result shirt, and shirt 2 is the tee that you'll get all the extra stuff from.
take shirt one and cut off the sleeves along the seam and then cut around the neck. Then cut shirt one along the side seams and along the top of the shirt (by the neck). You should now have 2 pieces that look like a tank top. Next, set your sewing machine up so you've got the zigzag thing going... and sew all around the neck and sleeves on both the front and the back. It should kinda look like the zigzag stitch is rolling the fabric under, and you want to stay really close to the edge. After that, you need your extra pieces. Take shirt 2 and if shirt 1 is too small, you can cut strips from shirt 2 to make it larger (that's why you cut up the side seams) If shirt 1 wasn't too small, then you know, skip that step. Then, if you've got a certain part of shirt 2 that you really want to be on shirt 1, cut it out. Then go around the outside edges with the zigzag stitch the same way you did the collar and sleeves on shirt 1. If you want to put something extra on the shirt, you want to do it now. I put a patch that I made from shirt 2 on the back. Just go around the outside with the zigzag stitch. If you have to extend the shirt a bit, take the pieces that you're using to extend it and zigzag stitch around the top and bottom. (the skinnier sides) Now, you want to sew the sides together. Since you want the seams to show, don't turn the shirt inside out. take a strip from shirt 2 and pin it to shirt 1 along the front piece of the shirt. Sew it with the zigzag stitch. Repeat with the other strip on the other side of the shirt. Then, you obviously need to sew it to the back... use the same method as with the front. THEN you need to sew the top bits together. you can turn the shirt inside out and do it that way like I did, or you can use the same method as the sides, it's up to you.
*whew* And then you're done. ^^; If you make one, post pics, I'd like to see.