I cleaned my sensor last weekend. I cut a small piece of micro fibre lens cloth and blew all the edge lint off with a can of compressed *dust off*. Then I locked the mirror up, and carefully applied a drop of pure ethanol to the middle of the sensor; placed the piece of lens cloth on the sensor face and used a water colour paint brush, washed in ethanol, to wipe the cloth gently over the sensor. I kept working it around until the ethanol was dried; turned the camera face downward to tip out the cloth, then released the mirror. Results are almost perfect. There's one tiny spot wandering around but it's loose.