Hidden camera suggestion

I would like to place a camera in my friends house because I go there often but I would like some help on where to place them and what cameras are good. I stayed in her house once and I was able to use my phone to go in her room while she was in the shower and hid it underneath her night stand. I got a good video of her getting out of the shower. I saved it to a external HD, i dropped it and now it won't read my files. I want to get more of her. Any help is appreciated. Thanks