no idea on the drawers, but it took DH all of 5-10 minutes to build me a bookshelf guard
it's just a board--half a 2x4, maybe? I'd have to ask him--cut to almost exactly the width of the shelf, and sanded to round the two opposite corners. like, if the board is facing you, the upper left and lower right corners are sanded. so it just sort of wedges into place in front of the books, and is rounded so as not to take paint off (though it has just a tiny bit).
it works for our shelves because they have a piece of trim in front, but it wouldn't work on all shelves. if it sounds promising to you, and you have the tools to do it, lmk and I can take pics/ask DH for details.
we have built-ins in our living room and the bottom two shelves on both sides are emptied, but the third one up on one side is DS's books. he has lots of board books he can play with, but when he started to be able to pull off his nice picture books, we needed a way to prevent that! and I really didn't want to move them because they're in a perfect spot next to our reading chair for easy access. the guard has been a great solution.