Hold the knife firmly and run the blade at an angle of 15 to 20 degrees, as if you were gently "scraping" the bottom of the mug. Do this 5 to 10 times on each side of the blade, alternating sides.

Opinel’s No. 7 is a knife you can afford to lose, not that you’ll want to. The heritage French brand has been making knives in the Alps since 1890.

Some cheaper ceramic knives are "actually really good," but if you want to get a good-quality, professional-grade knife, "you should budget for at least $100," he explains. Whether your budget allows ...