Hmm if you use a lens hood often, surprisingly, you dramatically lower the occurrence of finger prints, water marks etc, not to mention
flare!
But in any case, I also use a variety of methods to clean my glass.
1) My shirt, with and w/o my breath XD
Laziness pays off most of the time. Any clean spot of your shirt will often do. (100% cotton works well)
2) McDonalds Tissue
Works wonders, removes the oil/grease smudges. There's a bit of lint as the tissue rubs against the lens thread and spanner notches (if using a filter). Don't worry, it blows off easily.
3) "Pentax" Microfibre Cloth
Or any microfibre cloth. They work just as well as any other method. The reason why you get smudges is because the natural oils/dirt on your fingers gets on the cloth with use and eventually makes its way onto the lens glass. Just wash your microfibre cloth every once in a while with warm water + soap.
4) Blower blub
Use blower bulb to blow off dislodged dust bits, lint and other debris from front element / filter.
All done!