Salamandax requested some recommendations on brushes for applying foundations and concealer so here you go – sorry it took me so long! I have also included other tools that you can use, hope you guys find it useful.
Using a brush can make application less messy and is perfect for smaller areas that require more precision like the inner corners of the eye, around the nose and on zits. You also end up using less product. The downside is you have to wash them regularly and a good set of brushes can cost up to a few hundred bucks. Check out these tips on how to take care of your brushes so they can stay in good shape.
To apply foundation, I like MAC #190 Foundation Brush ($38) and MAC #187 Stippling Brush ($42).
For concealer, pick a synthetic brush with firm bristles. My picks are Sephora Concealer Brush ($16) and MAC #194 Concealer Brush ($18).