Shirts are the easiest thing to make. To make a shirt I use a shirt as a stencil to trace on fabric or pants. When using pants to make a shirt I tend to use pants that are too big for me unless I am making a crop top, then I recommend using your size leggings. To make the shirt using pants cut a hole in between the pant legs then fix to your liking. When using a shirt as a stencil make sure you leave space for seams when you trace the shirt.