Proper storage, usage, and maintenance.

Knives should always be stored separately to prevent the blade coming into contact with anything that could dull it.

Use the correct knife for the job. You wouldn't use a box cutter to peel a potato so don't use your paring knife to cut paper or open boxes.

When sharpening always ensure you have the right angle for the knife. Different knives have different angles depending on what their made for. If you don't trust yourself to keep the angle manually there are several tools you can find to help.

I mainly referenced knives but this is true for most things that are meant to be sharp. Razors, axes, needles, chisels. If it's got a sharp edge and you want it to stay sharp for as long as possible you have to take care of it properly.

Lansky sharpening kit. It holds the whetstone at the correct angle for you, so you'll get close to a professional sharpening with 0 previous training or knowledge.