I would invent a series of brushes with interchangeable heads. Why have three large brushes with heads when you can have one handle with three heads? The handles would come in three widths: small, medium, and large. Each handle comes with a case of brush heads corresponding to that width. The small handle brush case, for example, would hold heads like your thin angle brush and the slanted liner brush. The large handle brush case would hold your foundation, highlighter, and fan brushes. This makes a traveling makeup artist's toolkit more compact and easier to carry, leaving your kit open for more shadows, glosses, foundations, and liners that couldn't fit before because of the sheer number of brushes that you had to make room for before!
