You don't need a fully custom mask to make one feel like yours. A few small additions or changes can turn an off-the-shelf masquerade mask into something that looks specific to you and your outfit.
Add without overdoing it
The easiest customization is adding a small accent that isn't already on the mask — a single flower, a brooch, or a few extra rhinestones glued near the temple. The key is restraint: one added element usually reads as intentional, while several can start to look cluttered. A plain black or white mask is the easiest base to add to, since it won't compete with whatever you're adding.
Swap or add ribbon
If your mask ties on with ribbon, swapping the stock ribbon for one that matches your outfit exactly is a simple change that has an outsized effect, especially in photos where the tie is often visible at the back of the head. Craft and fabric stores carry ribbon in far more shades than any mask typically ships with.
Add height or movement with extra feathers
Even a mask that isn't a feather style to begin with can take a few loose feathers glued along one side for extra drama, without committing to a full feather design. This works especially well on metal masks, where the rigid base gives the feathers something firm to attach to.
Personalize a couples set
For a couples mask set, a small shared detail — the same ribbon color, a matching flower on each mask, or coordinating rhinestone accents — ties two otherwise different masks together without making them identical.
What to use
Clear-drying craft glue (not super glue, which can be too rigid and crack) works well for attaching rhinestones, small silk flowers, or trim to most mask surfaces. Test any glue on a small, hidden spot first, especially on painted metal or delicate lace, to make sure it doesn't discolor the material.