2. Take an old shirt to use as a pattern. Depending on the width of your pant leg will depend on what size of shirt you will be able to do. This probably won't work with a pair of straight leg or skinny pair of slacks unless you're a subscriber to the Angelina Jolie diet plan. Coke. [clear throat]. The legs of my slacks were fairly wide so it worked out pretty well for my wide mid section. Outline the shirt on to the wrong side of your pant legs with about a 1/2 - 1/4 inch for the seam. If you lay the bottom edge of the shirt on the bottom hem of the pant legs then you will already have a nice hem for the bottom of the shirt.
3. Cut out and pin together. Sew up the sides and the shoulders but don't sew the arm holes closed. I may or may not have done this and I may or may not have had to unpick the seam. Take the edge of your arm holes and fold them over towards the wrong side of the fabric, press, and sew all of the way around to make a nice hem. You can do this with the neck line if you choose but I decided to leave mine raw because I'm thug like that.
4. Embelish the front with the leftover buttons from the pants if you choose.
(if you're actually following along you'll notice the numbers in the pic don't actually match what I wrote)
Did you see my boston head print novelty top?