In the middle of a boarding fight, players need to find the captain, and a single gold bar on a sleeve will not do it. Design outfits one at a time and you get the opposite problem too: a crowd of individuals with nothing in common.
List the faction and its members the way you would in a design doc, such as an ensign, a lieutenant, a captain and an admiral. Layer settles the shared look first, meaning the fabrics, the cuts, the colors and the marks of status, and then gives each member an outline of its own inside it. You do not keep a style sheet of trims and colors to paste into every request.
Costumes that feel inevitable come from rules the audience never sees. A desert trading people wraps the head against sun and sand, shows wealth in brass and traded cloth, and marks status in who wears what. Settle those once and each character is quicker to design and looks like it belongs somewhere. Materials need reasons: every fabric should answer the climate, the job or the economy.
A good test for your own setting is to ask what an occupier would ban. The answer is usually the garment that matters most to the culture, and a character wearing it anyway tells players what they fight for.
Rank You Can Spot Across a Deck
Outline before insignia Higher ranks gain coat length, layers and one authority piece, so the admiral is clear before any badge is.
One soft piece Keep a costume mostly rigid with a single cape or sash, so the silhouette survives a turnaround and a rig.
Room for the individual Ask for one small detail per member, like a clasp or a stitched mark, and the crew stops looking cloned.
Taking Members Further
Every member arrives as its own high-resolution image for your art team. For modeling, turn any of them into a turnaround sheet. For each member's face in every mood, see expression sheets. For cosmetics of a character you already have, see character skins.