Something that I see people doing a lot is they'll start adding just top end to a master. They add some high end, and suddenly it's more open and louder, and then they add limiters on it, and they're done. I don't like it. That, for me, is a cheap gal: an easy trick to get something to sound louder and better instantly. It gets the job done, but weirdly. And you're never going to be able to get it sounding like incredible like that. You might as well just put it into LandR.
Now, what you want to do good mastering is not to add any top whatsoever. You want to work from the bottom up to the top, craft the low end and the low mid. Once I get that, that's where the feel, dynamic, and sexiness of a track are, where you get the beef and the solid foundation. I don't add any top at all unless I'm desperate. The top can do what it wants; it's not as important or as interesting.
Most people can get their mixes sounding great in the high end. Most speakers play back pretty flat in that area. It's only when we start getting below 500-600 Hertz, that the room starts getting involved. There's cancellation going on: it's super low in the subs, and they can't hear what's going on into the kicks. I'm in a position where I can listen to that and get that right. I then try and do as little EQ tweaks as possible. That's the other challenge I give myself. So it's adding no top and seeing if I can get away with two or three tweaks.
If I can, then I love it because it's like "Okay, I just took one little frequency out there, and boom!" But that depends on the mix; you can't do that with every one. But it's true that most mixes don't need a top end. When you start putting on top ends, you're fooling yourself. So try not to. As I say, challenge yourself: craft the low end and get the deep stuff happening and the low mids going. Once you get those cleaned up, the air will perceive everything else as a lot flatter and more balanced.
If you really want to add a top end, by all means, do that. But make sure that you've worked solidly on the lows, and then move on to the highs. Otherwise, you're in all kinds of trouble in the low end.