There's ONLY ONE WAY
It doesn't matter if you bake, broil, smoke, roast... brine, butter, bag, stuff, rightside up, upside down, sideways... ALL of these can = a moist or dry turkey
MEAT THERMOMETER & RESTING
MEAT THERMOMETER
When the internal temp is 180, it's done and it's moist/ SUPER juicy. You don't wait until it reaches 180, though. You pull it at 165 (unless you're smoking it, but lets assume you aren't). It will continue to cook (and temperature will rise to 180) over the 20 minutes you let it rest.
RESTING
When you first pull ANY piece of meat from the oven/grill/etc, the temp is rising still AND it's durn hot (steaming). The steam isn't just from the outside. It's happening in every cell. Cutting it while it's still steaming means that the steam ESCAPES. It lyses (cuts/explodes) the cells and the juices all run out. REALLY drying out a piece of meat. How long you let meat rest depends on the type, thickness, and cut. You wait 20+ minutes with turkey, but only 5 with steak, 10 w a 3-5lb roast, etc. ((HINT: If you poke it, like with the thermometer, and juices run out, STICK SOMETHING IN THE HOLE, and wait longer. The juices SHOULD NOT RUN. Or you haven't let it rest long enough.
So you cook it to shy of the 'done' level (changes for beef, pork, poultry... beef is the trickiest, because of rare/medrare/med/medwell/well... pork and poultry is easy peasy; 140 for pork & 180 for poultry), let it rest so the juices don't all explode out of the cells.
MOST people (even chefs) think a turkey is "done" (just looking at it) around 240 degrees. Nope!!! Even at 200 degrees the bird has started to reeeeally dry out. 240+ and it's super dry bird. WHY do even pros "think" a turkey is done ages and ages after it's done? Because we're all used to cooking chicken. A turkey LOOKS "chicken done" (chicken will be 180) waaaaaaaay after it's really done. So even pros use thermometers with giant birds (and tiny ones). It's because even pros rarely cook turkeys. People who specialize in turkeys don't need thermometers, but those people are few and far between. Unlike all of us used to chicken!!!