Before Picture:
After Picture:
What I did
First thing was first, the t-shirt was a bit ill fitting. So I tightened it by taking in the side seams. About 1-2 inches on each side. To do this, I turned the shirt inside out, made sure it was nice and flat, and marked where I wanted to sew. I made the markings with pins (You can do this with tailors chalk), all the way from the hem to the sleeve hem.
To sew the shirt to last, the best method would be to do a small zig zag stitch or serge (overlock) it. It will prevent the stretchy material from causing the stitches to break when it stretches. As it would do if you used a regular straight stitch. The two ways I suggested will also help prevent holes in your shirt where the side seams are.
The second thing I did was cut out the ribbed band around the neck line, just slightly cutting about an inch extra from around the sides of the neckline, to create a wider space for your neck and shoulders. Be sure to always cut less than you think you should when it comes to t-shirt cutting. The material is very stretchy and can easily be stretched out beyond what you originally had planned. Remember, you can always take more away, but you can't always add more.
The last thing you can do, which is optional, is roll up the sleeves for a neater look. Or you can also cut some length off, if you find yourself desiring thinner sleeves.
Godspeed and goodness to your creating! Have fun and make art!