Generally known tips:
1. Don't keep them in the kitchen drawer - their blades shouldn't touch each other.
2. Don't put the knives in the Dishwasher - again the posibility of their blades coming into the contact with other hard objects and also corrosion caused by dishwasher detergents.
3. Don't use any GLASS cutting boards - they look modern and aesthetic but they are very hard. Also, try to avoid hard plastic boards. The best cutting boards are wooden ones.
All the above are most common mistakes people make in regards to proper using of the kithen knives.
However, I would like to point out one more mistake people very often make not even aware of the problem. The blocks are one of the options for a proper storage of the knives - either timber or steel or plastic. But even those proper storage blocks can dull cutting edges of the knives.
The worst are the blocks that hold the knives at an angle. As a result the knife rests on its cutting edge thus dulling it over a period of the time.
The best blocks are vertically oriented, in which the knife hangs straight down not wearing the cutting edge. Be carefull though, if not used properly they can dull cutting edges, too.
Most of us when placing the knife into the block's slot tend to lean the knife a little bit and rest its blade against the edge of the slot. Then slide the knife inside using the slot's edge as a guide. Each time the knife is inserted this way, it "cuts" the hard edge of the slot. Doing this repeatedly will dull the cutting edge of the knife as well.
There is a very simple solution for that; always put the knife "upside down" into the block, i.e. keep the kife with the cutting edge facing up and rest it on the slot's edge with its spine (the thicker top part of the blade). Then slide it down the slot. This way the cutting edge doesn't come into contact with hard eges of the the block and in the case of "angle blocks" the knife rests on its spine thus not wearing the cutting edge.
Please, see the picture below.
