Choose the plane of focus
Identify the surface or feature that needs to be readable. Small movements can change its sharpness dramatically. Try moving the camera and subject together with care before assuming a narrower aperture solves every problem.
Control small reflections
Watch bright reflections on curved or glossy objects. Change the angle of the light or add a diffuse surface where appropriate. A reflection can explain texture, but an uncontrolled highlight can hide it.
Include a scale cue
Decide whether the image needs to communicate actual size. A familiar neighbouring detail can help, while removing scale cues may turn an ordinary object into an abstract study.