Anytime I'm shooting on a tripod with a relatively long exposure (faster than 1/200 maybe), I switch off IS (if available), turn on mirror lock and set the 2 sec timer. Also, I set the mode to One shot and a small enough aperture (f/8 - f/11). I focus on the subject using the Back button. And then carefully turn the lens to MF. I fire the shutter using a remote release. The photo is usually sharp. Now if only there was a similar algorithm for composition