Place first portal near edge of angled panel and second portal near barrier. While holding cube move to side and try to aim the middle of the cube to edge of portal.
Works with all angled panels.

Walk into funnel. Wait till you reach the end of the funnel and completly stop (wait and don't move on the wall for 420 seconds to be absolutely sure itll work, yeah...) and then:
- press and hold crouch button for flying
or
- press crouch ⇒ jump ⇒ relese crouch (flying without holding crouch)
If you hit the roof you can't get down and you can move only on the roof. Fizzler should help with getting down or placing portal if you used funnel with portals.

Once you fly with full speed press jump in the moment you hit the ground.

You can easly walk on the corners of the observating rooms and doors.

Place first portal near barrier and shoot second portal into existing one. Works with glass, grating, fizzler, laser field, light bridge and anything else up to 32 units between portals.

While laser beam goes thru the reflection cube you can pull out the cube below. You can also put a cube on your head and then use crouch to leave the cube in the air. As long as the beam is not interrupted the cube stays in the air.

While crouching on the orange gel move forward (or backward) a bit and stand up and you'll get maxium speed instantly.
PGCBG stands for Propulsion Gel Crouch Boost Glitch.

Place portals on the floor and jump into one. While you are passing portal shoot the same color portal on the wall. Once you fly out shoot portal on the floor and repeat.
Every successful reportal increases speed.

Grab cube, go near the wall, jump, drop cube about wall and jump on a cube midair. You can regrab cube after jump and repeat action.
Works also with other objects that you can grab. Here is good map for practice.

Simply just go into the blue portal (or orange) and shoot blue portal somewhere while passing thru. You have to be flipping while going thru the portals otherwise it will not work.

I just put a video here (cuz imma lazy bìtch) that I watched 6 years ago to learn BH by myself.
Here is good map to practice as soon as you understand the basics.

This glitch works only in co-op so here is the second video guide because I don't have friends... ;)

You can test yourself playing map I made specially for this guide:
http://cs2bus.com/sharedfiles/filedetails/?id=903662078

And if you are interested here's collection with my test chambers:
http://cs2bus.com/sharedfiles/filedetails/?id=901675984