Sharpening a culinary knife really is a personal thing, we have professional chefs that insist their Japanese knives are as sharp as a razor blade and have us sharpen their knives weekly. 

Others are happy to use our ceramic honing rods to align the cutting edge until they cannot slice a tomato effortlessly, then they have them sharpened once or twice a year. 

When you need a lot of force during cutting, this is a sure sign that your knife is blunt. A very wise Japanese Chef once told me ‘a sharp knife is a safe knife’.  If the honing isn’t helping then its time for professional knife sharpening.