Don't clean your object! We want dust, we want wear, we want objects that have lived a life.
Photograph your object using a plain uncluttered background. If you do not have a plain wall to photograph against, place a solid colour card / piece of paper behind the object.
Turn off the flash and use natural light if possible.
Use a tripod or rest your camera / phone on something to avoid shake and blur.
Fill the frame with the object.
Take multiple photographs at different angles to highlight important details.
If your object is a photograph / printed material and you have access to a scanner, use that instead of taking a photograph for best results.