The one thing I use to always hate to do was cleaning the front of my lenses! No matter how hard I tried to get the front element clean, it would always looked smudged after I was done!
I am going to explain how I clean my front lens elements, and what I use to give you the brand new, streak and smudge free look.
Before I get into this any further, it has always been said that cleaning less is better! The front element is a delicate surface on a lens, and you can damage the lens coating if you don't do it right. Remember dust on the lens element has to be extremely severe to show up in your pictures!! I have actually seen shots from a lens that was badly cracked, and you could not easily see from the pictures it took that there was anything wrong with it!! So my word of advice is don't obsess about dust that collects on it. The only time you really need to clean a lens, is when you say get a fingerprint on it, or perhaps water spots or other organic things coming in contact with your lens and leaving something behind, that could damage the lenses coating.
Firstly, before any cleaning takes place a good rocket blower is needed to blow away any dirt, dust and debris. The rocket blower for the most part is the only regular cleaning anyone really should be doing to their lenses. For finger prints and other contaminates that happen to get on a lens, I use a disposable Pec Pad and Regular Eclipse Fluid that is made for cleaning optics. This fluid evaporates very quickly, and really helps to leave a nice streak free cleaning. This combination will remove fingerprints and other contaminates very well. Another excellent product I use on occasion after the above, is a Lens Pen. This is a carbon based dry cleaner, that absolutely works wonders at cleaning the front glass. It has a soft front tip that you simply rotate around the lens to remove smudges and even finger prints. One of the cheapest tools to put in your kit, and an absolutely must have item for cleaning lenses. Most times it is unnecessary to clean the entire front element. I commonly only do a spot clean, if say a water drop, or perhaps bug excrement hits my lens(Being a Wildlife Photographer, this happens a lot). On a large lens element such as what you find on the big Canon Telephotos, cleaning the entire thing is a bit more tricky. What I do for my 500mm is stand it up on end, and with some Eclipse Fluid, and a soft cotton Q-Tip, I carefully remove the spot from the glass. I usually polish it up after with the Lens Pen, and everything is as good as new!!
That pretty much does it for cleaning lenses, and is what I have learned from my own personal experience. I hope that this will help all of you that want to keep their glass clean, and in great shape!