To begin by stating the obvious, it seems as though liver and other organ meats are no longer popular choices...at least not in the circles that I frequent. I guess that's because something like liver is a serious piece of meat. That is, it tastes like meat, and not like some bland carrier component for the other flavors in a dish (ahem, boneless chicken breasts). It doesn't respond well to cooking for too long. It can be a bit more temperamental than a roast or hamburger, and it certainly doesn't stay fresh nearly as long nor does it make particularly good leftovers.
It is extremely easy to cook, though, and it cooks up very fast. It stores well frozen, it's less expensive than most other muscular meats (even 'ground meat'), and if you take the time to look at the vitamin content of even a meager 4 ounce piece of beef liver, it might just blow your mind. This is a serious superfood.
The trick to thinking about liver preparation, if there is in fact a trick at all, is that you really have to accept the liver as the key player...the primary ingredient. Even a small amount added to a sauce and served over pasta will make the flavor of the sauce liver-dominant. That's fine - liver is also delicious if prepared well and served hot.
My favorite preparation is to simply pan-sear the liver in some butter or tallow, plate over whatever greens we happen to have handy, and top with a pasture raised egg or two. The egg yolk provides extra healthy fats to aid in the assimilation of the fat soluble vitamins from the liver (and also adds protein and nutrients of its own).