Right front pocket always, unless wearing a belt sheath. As I've only begun carrying a knife again and being a knife knut for the last two or three years they go in the right pocket because I have always always always put wallet and keys in my left front pocket , everything else in right front pocket, and I cannot/will not change that habit at this point. Over a dozen years of wallet carrying in the left pocket makes a habit that more firmly rooted than the knife carrying habit. I will not try a new wallet/keys carry method for anything. Nothing at all goes in my back pockets except slips of paper or a bandanna, but I've adopted Carl's method of putting the bandanna in my pocket with my knife and other items to keep them from falling out.
For the knives specifically, if they are small enough to go in the watch pocket, I tend to do that, with a Bic if the pocket is large enough. My GEC #15 fits the watch pocket perfectly. My other most common EDC is my Sodbuster, and at around 3 7/8 (I think) I would consider it a medium sized knife, not a large knife (although it's about the largest folder I carry now) and it is too big for watch pocket carry, so it just goes in the side pocket under the bandanna. The rare time I carry anything I'd consider a large folder, like my #42 trader, it sometimes goes in a belt pouch, but even a knife that size I'm perfectly comfortable with in pocket carry.
When fighting extreme exhaustion with large amounts of caffeine what could have been a three word post becomes two chunky paragraphs. So to summarize: Right front pocket.