Why the drawing happens near the date
People assume the six months is drawing time. It is not: your artist draws your piece in the four weeks before the session, and the rest is other people’s tattoos.
Drawing early sounds like better service and is worse. A design made six months ahead is a design made for who you were and what you wanted six months ago, and a meaningful number of people change something substantial in that window. Drawing near the date means the piece is current.
The two things that change during the wait
People change the piece. Not usually the concept, but the size, the placement, or one element. Somewhere around a third of pieces get adjusted at some point in the wait and every one of those adjustments is free because nothing has been drawn yet. This is the strongest argument for the long lead time and nobody ever makes it.
Some people stop wanting it. Perhaps one in twelve, and the deposit is spent. That sounds like a bad outcome and it is the system working: a tattoo somebody stopped wanting inside six months is a tattoo they would have regretted, and two hundred dollars is a very cheap way to find that out.
What to actually do with it
Print the reference at actual size and stick it where the tattoo is going. Live with it for a month. It sounds silly and it is the single most useful thing anybody does during the wait, because scale on a body is nothing like scale on a screen.
And do not fill the wait by getting something else somewhere faster, which happens more than you would think and is nearly always regretted by the time the original date comes round.