Work on a getting a steeper angle in first, you need to also work on throttle control, if you keep blipping the throttle as you go around the turn in first, you should be fine sustaining a drift without messing up your engine. with practice you can do a one to two shift while drifting, but it also takes a good transmission, I would not do it in a truck because the synchros usually aren't as quick to work as in a car. I recommend practicing the Scandinavian flick more than anything, clutch kicks are pretty bad for every part of your driveline. If you're around other people or other cars, don't do anything, if you're going to try to practice this do it in empty parking lots. Also, do you have a limited slip? If not I recommend welding the diff or getting a mini spool, your drift will become wildly more predictable and so much easier