Without sounding like a wise guy, nobody has addressed this fact. FIRST THINGS FIRST, MAKE A SALEABLE KNIFE!!
And by that I simply mean that awkward designs, thick and clumsy handles and poorly finished grinds will repel customers like angry hornets.
Assuming that you have surpassed all that, I started by selling knives to hunting buddies then quickly moved to forums because hunting buddies only want to pay "buddies" rates.
When chosing a forum to sell on I can't emphasize enough that your work must match your customers expectations. If you build zombie slayers, stay on the forums that cater that way. Keep in mind that there is a customer for every knife ("A butt for every saddle") but ask yourself, At what price? When you start off, if you can double your costs, you may be happy enough to move it. Every knife in someone elses hands is a built in salesman.
Be aware that selling on forums such as this one, we do have a growing number of collectors but you are basically trying to sell knives to knifemakers. I for one, am happy to add to my collection, but it has to be at an exceptional price.
Work on your website, explore ALL the forums including hunting, camping, survival, Jeep owners etc until you land on a good customer base.
One more tip "LET "EM SOAK" meaning don't get jumpy and lower the price every week. You only need one buyer to make a sale. Give him time to find it. I just recently bought online and watched the piece for three weeks until it went to half price. My wife said, "if you wait long enough, this guy will owe YOU money" Don't be that guy.
Just my opinion,
hope it helps,
Steve