Applying foundation with your fingers is a big no-no, cautions Laura. If you do, then you'll inevitably slather on more than you need, and it'll appear uneven.
Sponges are best to apply foundation. Using a sponge, you can dab foundation on with control, and sponges are relatively gentle on your skin. Laura says to dab foundation "here and there" to even out redness or other discoloration.