I recommend the Picasso spatula.

I like using a spatula when doing base makeup because it allows me to apply thin layers multiple times!

I used to just use a puff for my makeup, but I found that applying a thin layer of foundation with a spatula and then patting it in with a puff made the base look much thinner!

It took me a long time at first because I wasn't used to how to use it, but after doing it two or three times, I quickly got the hang of it.

Even if it isn't a Picasso spatula, there are many affordable versions available at Daiso and other road shops these days, so give them a try!