My first instinct is to offer to go with her next time, although that doesn't cover how to say you really dislike what you've already been given. Maybe explain apologetically that you have very particular and difficult taste in such things, but you'd be happy to go along with her to choose something together? If you team-shop enough, she might even learn how to pick stuff for you eventually.

Some people (my hubby included) hate surprises and would be happier knowing what's coming; if that fits you at all, you could play it up.