The three shapes you picked, with crystalline dropped. Every treatment here is built from real geometric cuts — the shape is sliced and a thin band deleted — so the gaps are actual holes, not background-coloured overlays. They therefore survive on any wallpaper and in the flat mono mask. Small tile under each is 40px.
Variations on the perched bird: posture, direction, and how much of the bird the frame keeps. Solid for shape, outline for the same shape as line only, then 40px.
Your current favourite, varied on the things that actually change its character: wingspan and how much it fills the tile, sweep angle, how many slotted primaries, tail shape, and rotation. Solid, cut, and outline for each.