Originally posted by PointBlue:
You have few options for lens cleaning solutions.
If you do not want any contact with the lens at all, a blower is advisable to blow off all the dust on it. If you have stains however, you can use a lens tissue (the special kind) or a microfibre cloth like those used to clean spectacles. Sometimes, there will be a cleaning fluid provided with cleaning kits, but used only those meant for photography.
A cotton bud is non-advisable. It has a tip which may potentially scratch the lens coating and damage it. Water is to be avoided at all costs.
If you already have water on it, use a tissue to wipe the water off and then use the aforementioned methods. If your lens has a filter thread, buy a UV or Skylight filter for your camera to protect the lens.
oops..i've already cleaned it wif a damp cotton bud

so i just go ahead and clean the lens wif a spectacle cloth..