Generally speaking, your knife does not need a lot of care. With a few common-sense tips, your knife will not only last your lifetime but that of your children or whomever is lucky enough to have it passed down to them. Clean your entire knife after use, not just the blade. Blood or dirt left on a blade for a long period of time can mar the knife finish but can also damage the hinges or locking device on lock backs.
Oil the hinge or pivot points occasionally. A very fine coating is sufficient. Once you have achieved a sharp blade, maintain the edge alignment after use with a sharpening steel. A few occasional strokes with a steel at a 30 degree angle will keep your edge sharp for a long time and significantly increase the time between when your blade needs to be sharpened. You can then apply a thin coat of lubricant to the entire surface of the blade. This helps prevent any surface oxidation and corrosion from moisture.
Keep your knife away from extreme heat. Excessive heat can cause the handles to deform or crack and in very extreme cases, the steel to lose its temper (the ability to hold an edge.)
Use your knife for what it is designed for – Cutting. Don’t use the blade for prying, opening cans, as a screw driver, etc. This is not only bad for the knife, it could be bad for you as you might hurt yourself. It will also void your warranty. Keep your knife sharp, a sharp knife is much safer than a dull one.
On multi blade knives, open only one blade at a time. This will prevent damage to the springs that hold the blade in place.