When you get where you like it then you are on your way.
Pictures will tell you a thousand words about your own knife. Your eye may miss something but the camera don't lie. If there is a flaw there you will see it in the pictures. I have taken pictures and looked at the pics and had to go back an look at the knife and sure enough what I saw in the pic was a flaw I had missed it with my naked eye but, the camera didn't!
I use to do construction and had a boss one time tell me the mark of a craftsman was not, not making an oh oh!
Rather the mark of a craftsman, was that if he made an oh oh, that he knew how to fix the oh oh in a way that did not lessen the quality of the piece/work and that the fix, improved the piece and it was done in such a way that only he knew that their was ever and oh oh there!! Now that sounds like a rather tongue in cheek analogy till you actually pull it off!!
Personally a piece with flaws, I would rather not sell.
I had a friend that saw a knife I made and loved it, wanted to buy it. I explained yes but their is a flaw right here and even after pointing it out he still wanted the knife. I told him, here is what I will do is I am gonna make you another piece just like this one, without that flaw and I will sell you that one! His response was but no one will ever see the flaw. Maybe not I said but, I know its there!!
My father used to say do a good job and your name gets around fast enough, do a bad job and your name will beat you from job to job. He told me that when I was about 14yrs of age and I still try to live my life by it!
I think if you go to any maker and ask to see his drawer of the rejects he will show you them and laugh. The thing you will notice is that as he got more skilled the ones the went into the reject drawer, well............... it got harder and harder to find the flaws but, he still put them in the reject drawer!!
I showed one of the first knives I ever made to a MS. At the time I did not know he was a MS or even what that meant. He looked at my knife, tuned it over, felt the balance. Looked at the blade, asked some questions and looked at me and said, "it's a good user"!
At the time I took that as a compliment and I think it was meant that way. However it wasn't till years later I realized, that was the kindest thing he could say about the knife!
The guard was silver soldered on and the solder had poured in the guard where I had cut the slot too large, the handle was ill fitted and I had burnt the wood in the handle by getting the rivets to hot when grinding them down. I still have that knife and it has skinned many a deer. So it was a good user but even after I re-handled it a few years later, it is still just a good user! But I have learned a lot since then!
When will you know? You will know when its time, if you are honest with yourself!!!