i trim my packers to 1/4 inch, plus pulling out the big eye of fat on the side of the flat.
aaron franklin does a good job explaining it here. the piece i'm talking about, he takes it off at 19:50 in the video
also, don't split the point from the flat until after cooking the flat, thats just weird
i cook the thing whole until the flat is done. pull it off, split it from the point and wrap it and put it in a cooler for an hour or so. take the point, cube it into burnt ends, back on the smoker for another hour while the flat rests in the cooler.