General protocol: always begin and end with a backstitch, and sew 0.5" to 0.625" in from the edge of the fabric. You might have to exercise good judgement about this, if you're like me and stuff is starting to not line up perfectly. Luckily the seam allowance should take care of any mismatching sizing. Just roughly make sure that you're being symmertrical, and have smooth lines....
Begin on the front panels. Start at the outside bottom corner, and sew inwards along the bottom of one panel, then up the center (where the buttons / holes will go), and continue around the neck, down the other side, and across the bottom. Don't go up from the front's far outside bottom corners!
Also sew the arm holes together (two large crescents, if you lay it all out flat.), and then the bottom of the back as well (but *just* the bottom). Sew an upside-down V in the bottom center of the back, to look cool.
When you're done, take out all the pins, trim the seams, and cut notches into the inside and outside curves so they'll sit better when it's turned inside out.