I just can't, even in otome games that are specifically made for self-inserts (like Amnesia, for example). Maybe it's because the heroine doesn't act the way I would, so it creates this sense of dissonance for me.
I prefer to see the heroine as a separate character with her own thoughts, actions, dreams, and etc. I'm also more drawn to otome games where the heroine has a strong personality. It's much more interesting this way.