Maybe I'm crazy (actually I know I'm crazy), but I put a lot of emphasis on a bookmark. I feel it can set the tone for when you return to a book. What do you use for a book mark? Do you, fold the corner of the book? Use a scrap piece of paper? Buy a fancy billion dollar bookmark? Make a bookmark? Use random objects as bookmarks? I personally use paint chips as book marks, because I like to collect paint chips. I have a set of children's paint chips in the shape of mickey mouse which I'm using. I always carry a few around with me in case I stop at the library and decide to get a book. If I don't have a paint chip handy, I'll use a scrap piece of paper, or I'll fold the edge down.
I usually use a piece of paper, but I just got this really cool bookmark from the library that I now use.
I usually use new stickers, because it's pretty much what i always have handy. Feels nice to open a book and be greeted with "don't overwork yourself at you summer job"
I cringe every time I see someone fold the corner of a page to keep their place. Just use a scrap of paper, so your book doesn't end up a creased up mess. And fancy bookmarks that are too thick can damage the binding.