I don't usually bother binding stuff like that (except mounts.) I have mounts and chocobo stuff other things I only use occasionally off to the side on the vertical bars. I have mounts bound to "." and "," (ground and flying) and I just click the rest. I don't even have Return on a bar. I just type /return when I need it.
I don't always. But my MMO setup is pretty standardized at this point. Those bindings are based on WoW where it was advantageous for me to bind mounts and my hearthstone and crafting windows and such.
As a for-instance, my primary (unmodified) bar works like this:
1 - 4 are rotational abilities
5 is an aoe
6 is an execute
7 is an interrupt
8 is a snare
9 is a finisher of some kind, usually a late class ability
0 is a primary dps cooldown
- is a movement ability
= is a ranged attack
On ranged classes - and = tend to be a little different, but the basic scheme stays the same. And I keep this setup between games and between classes. This way I'm able to pick up a game I haven't played in years and it isn't a problem because even if I don't remember all my combos right away, I can play the game without missing a beat. It also lets me play every class without being really confused all the time.
There are other rules for my modified bars... SHIFT tends to be heals, tertiary rotational abilities, and dps cooldowns. CTRL tends to be defensive abilities and cooldowns. ALT tends to be short-term self buffs and party/raid-wide cooldowns. I try to keep major cooldowns to the 8, 9, and 0 keys. I try to keep aoe abilities to 5 and 6. It doesn't always work out perfectly, but then all I have to learn are the exceptions.
EDIT: Also I'm using one of these things to do all that. I'm not some horrible tentacle monster. Edited, Jun 13th 2016 11:11am by Callinon