That 8x10/360mm is a very good combination for LF portraiture. As to overall technique, I think the best way to get the portrait you want with that camera is to get a rapport going with your subject. Talk to them for a few minutes before putting them in front of the camera, so that they're relaxed and ready to shoot. Give them a little advance prep as to what to expect, so they understand what "sit still" REALLY means.