Keeping your ATV looking and running sharp isn't tough to do. The biggest part of that job is simply washing your ATV after you ride. When you're done riding for the day, wash your ATV and dry it, microfiber towels work great for this as they absorb moisture without leaving any lint or fibers residue. Use a stiff brush if necessary to remove dirt and debris from around the chain of your ATV.
Another way to extend the life of your ATV parts is to grease moving parts. The bearings are a great example of this. They get wet and often do not get greased and you need your bearings in your ATV running smoothly. Also, greasing the bearings of your ATV will push any mud and dirt from around the bearings themselves.
Check your Upper and Lower Arms to see if they need fittings or greasing to keep them working in tip top shape. Other places that will need to be cleaned and greased on a regular basis for maximum performance are the steering column bushings and the real axle bearings.
A tip for when you are adding a fitting on a bearing, do not add the fitting exactly on top of the bearing. The fitting should fit neatly beside the bearing. Make sure the bearing is not sealed, the grease that you put around can't get into a sealed bearing.
Keeping your ATV both clean and greased where the moving parts are will extend the life of your ATV and give you years more service out of your current ATV model.