Best $23 I ever spent on a makeup brush or tool was this Beauty Blender Makeup Sponge.
I won’t ever apply foundation (cream or liquid) again without this sponge if I am going to a serious event or an interview.
You soak it in water, squeeze it a few times, dab it in the cream or liquid and then sponge it onto your face. It gives your foundation an airbrushed look, it stays on better (less oils from your fingers getting onto your face), and it looks INCREDIBLE.
I set it with a light dusting of powder, and I was good to go.
It lasts for the entire day, even through my sweating (literally and figuratively during my interviews), and my skin looked airbrushed.
From afar, it looked like I had perfect skin. Up close, you could see the bumps (obviously) from my pimples (hormones getting all out of whack post-baby), but when I got back home, I looked in the mirror and marveled at how great my skin looked.
Even a stupid makeup n00b like myself, was able to apply the foundation flawlessly. No brushes or anything needed.
The only caveat is that I suggest you apply your concealer first, and then the foundation, otherwise you might have to let your skin dry a bit before applying another layer of foundation with the sponge.