Ham is super simple. All you really need to do to one is slowly warm it up and keep it moist.
For superior ham, toss a glaze on it and maybe caramelize it a little. Just be careful not to burn the glaze.
The sweetness/heat/citrus of a glaze combines with the saltiness of the ham to provide extra goodness.
Here are a few glazes to peruse:
5 Easy, 3-Ingredient Glazes for Ham . I will probably do either an orange or pineapple glaze this year. Orange sounds good to me tonight but we'll see.
Another fact to consider with ham is spiral vs. uncut. I prefer uncut hams because they retain moisture better. If you are using a spiral ham, you may want to put a water bath in the oven/grill so the ham does not dry out on you.