First, download the VSCOcam app. Open up the camera in the app and place two fingers on the screen. You should see a focus icon and a exposure icon. Lock focus first and move the exposure icon around until your photo looks bright (it's important to get your photo bright before you take the photo).
Next, hit the wrench symbol to edit your photo. Then I adjust exposure (sun icon) by making my photos a little brighter.
Then I add contrast. Be careful not to add too much.
Last, a tiny bit of sharpening.
That's it! Less is always more when editing and starting with a clean, well lit area makes all the difference. Here's my finished photo.
Here's a wonderful video resource for using all the other features in the app.