Refashioned Coco Sailor Mini is crafted with Tailoring in Mabinogi (clothes). This page lists everything needed to make it, checked against the game as it exists today. The interactive planner lives in the Tailoring Companion.
How to get the sewing pattern
The sewing pattern is rank 4 and survives 30 uses; every crafting attempt spends one use.
Sayiv: Talk to Sayiv on the docks of Port Qilla and open her sewing pattern and manual list to buy them directly.. Payment is in Seasonal Ducats, earned through Season Trading.
Materials
Expect about 7 attempts per finished item (15% average progress per attempt). Per-attempt materials are consumed on every attempt; finishing materials once per item.
Each attempt uses
1× Fine Silk — weaving on a loom, low-mid rank
2× Fine Leather Strap — weaving rank 6 on a spinning wheel
Finishing (once per item)
1× Common Finishing Thread — Buy directly from any general goods NPC shop.