That is entirely up to you. Some basic essentials are a foundation/all-over face brush, concealer brush, powder brush, blush brush, eye blender brush, basic eyeshadow brush, eyebrow brush, and a small angled brush. However, many brushes can have multiple uses. For instance, you could use a blush brush to apply bronzer. If you are a makeup artist or enthusiast, you may wish to own a large collection of makeup brushes, each of which is tailored to a specific use. But if you just want a set of makeup brushes for everyday use, a well-balanced kit of ten to twelve brushes would likely suit your needs just fine.