- Knives. I've mentioned my one kitchen rule before: Don't put knives in the sink! To summarize, if you put a knife in the sink, it may be covered by water, soap suds, or other dishes, which obscure in from view so that an unsuspected soul who reaches into the sink may lose a finger. Also, knife blades can get banged out of shape by a stainless steel sink and all the crap put into it.
- Wood cutting boards. Wood cutting boards should never be submerged in water. It ruins them. Clean a wood cutting board by quickly sudsing it under running hot water, and then dry it immediately and thoroughly.
- Cast iron. One of the quickest ways to ruin cast iron is to expose it to water. Most cast iron can be cleaned by wiping out the grease and gunk with a paper towel, or by burning off any crud (which causes excessive smoke, but occasionally needs to be done). Some people recommend cleaning the interior with salt. Whatever you do, never put any cast iron pan or skillet into a sink, where it's always inevitably wet. And please for the love of all things good in this world, never let water stand in a cast iron pan, whether it's in the sink or elsewhere.
Instead, leave your cutting board next to the sink with your knives resting on top of it until you're ready to wash them. Leave your cast iron pan on the range top until you can wipe out the grease and gunk with a towel.
Take care of your things, and they will last longer and work properly.