Charge Boost (CB)

The Charge Boost involves gathering momentum by running into a wall/vertical surface for some time.

How to Do a Charge Boost
Difficulty: (fairly simple, but difficulty varies by Charge Boost point)

You need to find a spot that allows you to fly into the wall while still staying on the ground. Fly at it with your camera pointed at the ground, and watch for when your character flaps without jumping upward. Once you achieve this, keep at it; when you're ready, release the 'fly' button, and hold down both (controller) /  (keyboard - assuming default controls), and the camera angle. The longer you fly at the wall, the more of a boost you'll get.

Tips
If your wayfarer jumps, it means your charged momentum has been lost. If you see this happen, you'll need to start over. Once you get the position right, it's best to try to stay there until you've got the charge you need.

If you're playing as a White Cloak, keep an eye out for when your scarf starts to charge while it's still sparking. This means that you've hit the sweet spot. If the scarf starts to empty again, you've lost your charge.

Other things that might destabilize your include Sixaxis controls, moving around while charging (especially if you hit another walls), chirping, etc.

Videos
This video explains the three basic boost methods, including the charge boost, which starts at 1:48. CAPTIONS REQUIRED (EN + JN + auto translate). https://youtu.be/iikpj_2H9qg

Why Does it Work?
When you charge for your boost, the game thinks you're diving, even though you're on the ground. When playing as a White Cloak, it also allows you to charge your scarf while diving. This means that, if you can keep yourself steady against the wall, then you can "dive" indefinitely, which means that you can also fly as high as you want (with the possible exception of the ceiling - even the Broken Bridge seems to have an invisible ceiling).

Variations
Reverse Charge Boost (RCB) Dry Boost Super Boost