Round by round scoring, knees/legs to a downed opponent, and this isn't really in the UFC's authority but to get the judges to be less trapped by the 10-9 must that seems to have taken over. If you see a 10-8 round, score it like that. If at the end of the round you're scratching you're head about who won, or how the one guy survived all those attempts to finish, score it a 10-10 or 10-7 accordingly. Oh and lets get a little nuance it judging take downs, if a guy fails on 3-4 takedowns throughout a round and finally gets one in the last 30 seconds of the round, that shouldn't win him the round, although whole fight scoring would address this.
Those three things would do a lot of good for the sport.