Christmas in July: The Production Calendar Working Makers Swear By
If you press your first ornament in November, you've already lost the season. Here's the July-to-December calendar makers actually use to survive Q4.

The first year I sold at a December market, I started making stock in November. I sold out of nothing, because there was nothing to sell out of — I brought forty items to a market that could have moved two hundred. The women at the next table, surrounded by towers of mugs and ornaments, told me their secret with great kindness: they had started in July.
July is for decisions, not production
Right now is when you choose your lineup, and choosing is the work. Pick a tight collection — one palette, two or three product types, maybe a dozen designs from a Christmas collection — instead of forty scattered ideas. Test-press one of everything. July mistakes cost you a blank; November mistakes cost you a customer.
August through October: heads-down season
August and September are pure production: batch your cutting, batch your pressing, and stop redesigning (the redesigning urge is procrastination wearing a creative hat). By October you should be photographing and listing, because marketplace search takes weeks to warm up to new listings — the shops you envy in December did their SEO in the fall. Broader holiday designs earn their spot here too; Thanksgiving buys start surprisingly early.
November is for selling, December is for sleep-deprived restocks
If your calendar worked, November is shipping, restocking bestsellers, and politely declining custom requests that would eat three days each. December splits in two: personalized items die around the 15th (shipping cutoffs), grab-and-go items — cocoa-and-cookies mugs, teacher gifts, emergency ornaments — run hot until the 23rd.
The one-line version
Decide in July, produce in August and September, list in October, sell in November, restock in December. It reads obvious written down. So does every plan you only understand after missing a season — consider this your July nudge.