Any good-quality, lint-free lens cloth (esp. the microfibre type) will work just fine, as will lens tissue. Avoid using liquid cleaners of any sort if you can; if you must use one, then make sure it's a proper photographic lens cleaner, but99% of the time a 'huff' of breath is all you need. Regular household chemicals may do some really unpleasant things to the coatings on your front lens element.