So most people just use the typical foundation brush shaped like the one pictured above. But not many know there are a few different types of tool you can use to apply your foundation.
Synthetic fluffy brush
Flat top kabuki
There are probably even more than that so please correct me if so. I use a synthetic brush that is a rpunded kabuki type, i like this for foundation best because it blends it to a smooth finish and creates a flawless look.
Its best to just try out the different methods and see what suits you and your skin!
Using different types of foundations can also make a difference in what foundation tool you should use. As there are liquid, cream and powder foundations. I personally use a liquid foundation each day and feel a kabuki brush suits it more. Like i would suggest using a large fluffy brush for powder, and fingers always works better with fingers for me and then buff out with a large kabuki brush.
The classic pointed foundation flat brush is obviously a favourite with many and i also like this brush a lot, but sometimes it creates streeks on my face which i really hate the look of. And then when re applying more and trying to blend it a round it kind of drags the foundation and does not look very nice. This is why i would recommend a fluffy kabuki brush as the best one as it applys and blends the foundation.
Good luck finding the best tool!