The key to a long lasting relationship is care. These are all natural hardwood products that require a little love from time to time.

When ever possible, avoid prolonged exposure to heat and water. I recommend hand washing any and all wood cutting/serving boards to keep them looking fresh and prevent warping. Try not to soak your board in the sink either. 

Condition the wood roughly once a month (depending on use) with a food safe wood finish. When you start to notice the wood looking a little dull that is when you know to reapply some finish.
Use a food safe wood finish like mineral oil to bring your cutting board back to life. Apply a generous amount of oil and let it soak in for about 30 minutes. Dry/buff it off with a lint free cloth and it will look good as new! This should also help heal any battle scars your cutting board may have endured from use.