As described in this reddit post, you can add multiple custom binds by copying and renaming the file at:
C:\Users\[your username]\AppData\Local\Frontier Developments\Elite Dangerous\Options\Bindings\Customs.binds
Clutches are holding one button then pressing another, like Ctrl+S
. They're great for adding more bindings to the same number of buttons. Here's more details: http://www.reddit.com/r/EliteDangerous/comments/2y7tjv/option_to_bind_button_to_multiple_functions/
Everything below is the custom setup I use. It's based off of the "Control pad with yaw" control scheme. I tried to make clutches that complimented the non-clutched version of the button. Here are the differences from the "Control pad with yaw" control scheme.