I was definitely in the mood to sew today. I have been collecting Men's XL t-shirts in the hopes of being able to re-design/cut down to fit me.

So, I took one of my DH's discarded t-shirts and morphed it into a Kwik Sew 2900 t-shirt...View C. My version came out shorter.
Here's the steps I took:
1) I cut up the sides of the t-shirt:

2) I carefully cut around the sleeve and sleeve cap seams
3) I left the ribbed neckline alone and the existing shoulder seams
4) I folded the t-shirt lengthwise, matching the shoulders and neckline and bottom hems.
5) I took my KS pattern pieces front and back and placed the pattern pieces on the fold of the t-shirt:

6) I carefully cut out the front and back. Notice the ribbed knit neckline and shoulder seams are still intact:

7) For the sleeves, I placed the KS sleeve pattern over each sleeve and cut the new piece out:

Here's a picture of the before (top sleeve) and after (bottom) for the sleeve. Notice the nicer sleeve cap of the bottom sleeve and the sleeve hem is still intact:

8) I serged the new sleeves flat into the new t-shirt
9) I serged the sides of the new t-shirt from the underarm of the sleeve to the side for the left side and the right side.
10) Hem the new t-shirt.
Since the typical RTW logo t-shirts have very little stretch, I ended up tracing a Medium in this KS pattern. I shortened the pattern length at the bottom by 2 inches. I usually use a size Small when the knit fabric has quite a bit of stretch.
Here I am modeling my new RTW t-shirt. Notice I have kept the vendor's logos (front and back) where they should be:

DH was quite impressed with the outcome and how quickly it was sewn. He asked me if I had taken a "before" picture of the XL t-shirt on me. Well, I forgot. I was caught up in my sewing mood that I forgot. DH has offered to dig up another XL t-shirt from the same vendor, but in a different color. I will be back to post what the before t-shirt looked like on me so you can get an idea of the difference in size.
I'm off to cut up some more XL t-shirts, including one from my recent trip to Seattle.