I know that this technique in particular can be very different from one lineage/school to the next. Recently while at the local school here my sifu asked me to give him "bong sau" energy with his arm in tan and mine in fook. My training previously taught me that bong can be used for many different occasions, depending on the placement of both arms, and the direction and force of the energy. So naturally (since i was on the outside of his arm, I simply punched from a flanking line) He told me it wasn't "bong" energy. He said do it again, so I did it again....apparently wrong again....so this next time I simply pressed my fook down and foward (as if shooting for a center palm or punch) and he said "YES!" that's bong energy! He then asked me to perform bong sau on his punch, and so I did, but I don't think he liked the way I did it...

I always perform bong with the arm upper arm parallel to the floor, forearm pointing a bit forward so that the hand is further out then the elbow, with the palm relaxed and facing forward a bit...wrist directly in front of the centerline. Just like in SLT, If I were to simply drop the elbow I would be in a perfect tan shape. My "energy" (or at least what I try to do everytime) is that of a springy energy, wherein if the force being put on my bong suddenly disappeared, my arm would probably do a fak sau with natural tension.

This is how I've understood bong to be over the years. Now since I was out (from doing martial arts) from late 2001 till the recent fall season, I'm sure I may be a bit rusty.

As far as when to use bong sao, I tend to use it naturally only when I have to, should I not be in a good position for tan, and if the energy is coming on the outside high gate, and slightly inward to my centerpoint, with it pressing on my bridge, I will roll into bong and lap da (or some other variation) instinctively. This is still what I do naturally, I don't care if the hand form is a punch, or press, or whatever, if I feel it then I do it.

What are your takes on this guys? How do you go about doing things?