Even when she was young and popular, I've always felt she was underused, she never got the major roles. Even in The Lord of the Rings trilogy, her part as Arwen was quite a small one, Miranda Otto had much more screen-time by just appearing in two movies as opposed to the three pictures Tyler did which were basically two minutes per movie.

Liv Tyler owned the screen in those 2 minutes though. The impression left by her work in that series totally overshadows Miranda Otto (who, by the way, is much more memorable in her little bit part in The Thin Red Line. Funny how that works).

Her role was still expanded comparing how little of Arwen we get in LotR books and Aragorn and Arwen story is just in the appendices. About overshadowing Miranda - completly disagree. Her scene with Brad Dourif in Two Towers alone is acting-wise much tense than anything Arwen is involved for 3 movies. Liv is descent actress, but stands nowhere near Otto, who is acclaimed and talented performer, mostly theatre and movie wise.