I'll just add that packing isn't a "figure it out, then forget about it" kind of thing. For me, it changes with every different blend I smoke -- and I smoke a lot of different blends.
The cut of the leaf, the constituent tobaccos in the blend, the degree of moisture content -- all of those will demand a particular approach. And that isn't even taking things like flakes and plugs into consideration.
I think this is part of what makes pipe smoking enjoyable -- adapting whatever I've been able to learn to fit each situation in order to get the most pleasure from each bowl. But I will admit that sometimes I just want to jam a wad in a bowl and smoke it!
Bob