I do exactly the same fionas! If its potentially dangerous or similar (as in things could get seriously broken) than I will stop her, move her away with my 'phrase'.....but she too loves emptying the bookshelf...........oh and this morning, she ripped up the whole foam mat we have in the play corner, which is fine by the way - its one of those ABC mats that are supposed to come apart etc, so a functional toy I tend to keep her away from drawers coz while some drawers are ok as to their contents, there are others that would be bad to unload iykwim? so I don't want to confuse her as she can't differentiate between the two concepts of "good drawer, bad drawer"

But you're right in saying picking your battles as it were. I think that R&Bmum has it right though in keeping on with the manners & communication barrier (signing) though.......I think that's a really important aspect to eventual sanity for both bubby and parent