If you are using liquid foundation, pour a small amount into your palm, then mix it a bit using your finger. Next, "paint" stripes of foundation down your nose, across your forehead and cheek, and dot some on your lids and chin. Blend upwards and outwards using a sponge or your fingers.
For powder foundation or pan-cake foundation, soak your sponge in water, then squeeze out the excess. Glide the sponge on top of the foundation, then apply onto your face using upward and outward motion, starting at your nose.
For demostration, I only apply foundation to my face, but you should also apply onto your neck, chest or ears, if they are showing. If you don't, you will look like you are wearing a mask!
Wheeee! The attack of the Blotchy Foundation! Sorry for the unevenness(?), my foundation needs to be thrown away...