1. Go into preferences in safari, advanced and check the box that says Enable developer menu in menu bar"
2. VO M, go left and scroll down to "System Preferences", go to keyboards and select the "Keyboard Shortcuts" tab. Now find "App Shortcuts" in the first table, tab across and find "Add".
3. Select "Safari" in the drop down box that appears.
4. In the following field "Shortcut Title" type:
This has to be exactly as written above, capital D, J for Java and S for Script, no space between Java and Script. Just copy and paste, save yourself the headache. It has to be correct as it is calling the function.
5. Now move to the "Keyboard Shortcut" field and perform your preferred shortcut, I use Shift, Command J.
6. Hit "Add" And you are done.
Capital D and capital I. Unfortunately the shortcut, shift, command an I is already taken, so I use shift, command, option and I to toggle images on and off.
And there we have it. Any similar tips in the comments below. Let me know how you get on and if you do have any problems, give me a shout.
When adding the shortcut, don't panic when command tab doesn't work, I believe this is a bug. Simply closing the window with command W will sort this.