My pipe club holds smoking contests about once a month. Our president is Mike Doc Garr, he has been the North American pipe smoking champion several times. Hopefully once again this year, the contest is in a couple days.
We talk about chasing embers more as an observation than a technique. If you go to a big contest youll see alot of people cupping their hands around the bowl to try and see the ember. You want a tiny ember on the top of the bowl, it usually goes down and comes up, but you want to keep it on top, and it goes around the bowl in a circle if you do it right. so you are chasing the ember, it is mostly luck on how it works, but if there is any one thing that helps the most its the packing method. If you get that wrong you lose.
Thats about all I can give you at the moment, you can pm me if you have any questions and anything I cant answer myself Ill ask Doc and he'll give you an answer, I see him on thursday