That's definitely an inherently huge challenge and massive problem with writing characters greater than oneself (be it more beautiful, stronger, smarter, more creative, more valiant, braver, more determined and so on) and to some extent even just different. I think this may be partly why Tolkien deliberately chose Hobbits as the main protagonists, and not say Gandalf and perhaps why so many internal details of elvish kingdoms and the workings of the Valar are not directly divulged, to the extent of influencing the Hobbit and the framing of LotR. (What mortal would dare gainsay his betters by far?) It's worth noting how carefully and how long he took to write the Silmarillion for example. It reminds me of a quote by Dirty Harry (? I think) 'A mans gotta know his limitations' (which can be considered a modernized version of 'know thyself' combined with 'nothing too much'), and probably holds as true for artists as anyone. Elvish artistry must be almost incomparable.