Someone should make a sticky for Paul's topic about stunting in the chat and support section of V. Cannot even find it with my slow net atm
In general:
-Holding a wheelie makes you go much faster.
-The ruffian is slower than the Bati but can bump higher objects.
-"Gliding" helps gain distance and height in the air. This is what you see in most videos (the person flying upside down 'hovering' while going back and forth a bit).
-"Airgrabs" (which are not airgrabs at all and should be called ditches/bails) are lame (IMO) and ruin good stunting spots because people are too lazy to actually land them while staying on their bike. Unless the object you land on is smaller than a bike it's fine though but in general these ditches are a no-go (again IMO).
-The ability of Franklin is handy for beginning stunters but I highly recommend not using it. Most people dislike it because it makes everything much much easier. So to see someone land the stunt you have been trying for ages with that ability is kind of frustrating. For instance some stunts I have landed (or yet to land) take several hours to land but with the ability it takes a mere 4-5 tries. So unless there is a good reason to use it, avoid it. It also looks pretty bad (imo).
-Don't use GTA race boost unless you absolutely need to. So on very very high wallrides, but on nearly every single other occasion they are unneeded and should be avoided.
Hope that helped a bit.