I'm in slacks five days out of the week, so my multitool is usually a key chain SAK, or maybe my Executive, which I just found after misplacing for an entire week! On a related note, I am shocked and appalled that it didn't fall out of the pocket of my pants that were hanging in the closet. Back on topic, my smallest multi, a Skeletool, is too bulky and hole forming for slacks, so I carry something a little more pocket friendly.
On weekends, jeans and shorts. Even in winter, because California. My rule is, if I have extra pockets, then I'll clip my multitool into one of them. As it stands, my phone, keys, wallet and bandanna all go into different pockets, with no room leftover for a multi. So, I take a multi whenever I have cargo shorts. Otherwise, it's typically the same as my weekday carry. I'm also working on warming up to a Swiza D04.