Normally, I scan directions to see if there is something very different than normal construction. Otherwise, I construct in segments ... ie: blouse front, front placket, darts, etc & then the back. Next I'll construct the collar & collar band, add cuffs to the sleeves, etc. Last of all, I'll put all of the parts together starting with shoulder seams. I usually put sleeves in using the flat method with side seams & the hem being the last thing that I do. Buttonholes are done before I add the sleeves & side seams. It's just easier for me. Basically, the bias tape around the collar on your pattern, SM, will be less bulky than sewing a seam when there wasn't supposed to be one. Costumes are not couture sewing. I'm sure that you will do just fine.
Marty
Brighten each corner where you are ... smile!