XXL Tee before:
Set out shirt inside out
Place a loose small tee over the XXL tee and trace
Pin the sides of the shirt
To get the right size for the sleeves, I used a sleeve pattern from a project I did in the past.
The top is the "before" and the bottom is the "after"
With right side up fold sleeve, pin and sew (do this for both sleeve pieces)
Now you're ready to sew all the pieces together!
Sew up sides first (your shirt should still be inside out). Turn both sleeve pieces right side out, and insert them into the arm hole (kind of hard to explain, see image below for guidance)
pin sleeves to arm holes and sew around
Add pocket: cut a 4'' by 4'' square
Fold down top 1/2'' and sew, fold in remaining 3 sides 1/4'', pin on shirt and sew