I have a "quirky" way that works 100%, but like I said its got a quirk or 2.
First add the EQ2Execute to MCP Customs as per BJCasey's post in this thread:
http://www.isxgames.com/forums/showthread.php?t=5197
On the combat "tab" creat a button, mines called "Fly"
Select Command: EQ2Execute
Custom Button Name: whatever you want
Additional Parameters: follow toon_name [this should be the name of the toon who normally lead your group around]
use OFollow when not flying
when I want to fly, I induce the bug in OFollow where if you click OFol--- 4 times they stop following, then click my fly button.
Sometimes they don't land completely, but I just click Fly-Dn and continue with what I'm doing.
If you engage in combat while flying, you might have to click you fly button again to get them to follow. I have 1 toon out of the 5 that always stops following because of combat.