So now the practical example would be making macros that have the cure icons with cure potions like Ashley asked here.
First it's easiest to make some placeholder macros.
1. Open up your macro window (press O)
2. Create four macros and call them "Cure Trauma", "Cure Arcane", "Cure Noxious", and "Cure Elemental"
3. Give each macro one step by dragging a spell from your knowledge book (press K).
4. Now put those four macros on four open slots on a hotbar. It's easiest if the four slots are next to each other.
Then we're going to save the hotbars and edit them outside the game.
5. Type /savehotkeys hotkeys.txt
6. Go to your EverQuest II folder and open up hotkeys.txt in any text editor. Notepad is fine for this.
7. Scroll down until you find the four slots with the placeholder macros. For me it looks like:
6 6 macro -65536 2 1 Cure Trauma
6 7 macro -65536 2 1 Cure Arcane
6 8 macro -65536 2 1 Cure Noxious
6 9 macro -65536 2 1 Cure Elemental
This is hotbar 7, starting from slot 7, because computers like to start counting from 0.
8. Now on each line that has the word "macro" paste these text lines over the rest of the line, starting from -65536:
20709523 1 1 Trauma
20709526 1 1 Arcane
20709524 1 1 Noxious
20709525 1 1 Elemental
I grabbed these icon numbers from my fury.
9. After that your macro lines will look something like:
6 6 macro 20709523 1 1 Trauma
6 7 macro 20709526 1 1 Arcane
6 8 macro 20709524 1 1 Noxious
6 9 macro 20709525 1 1 Elemental
10. Save this file and close your text editor. (It's important that the macro names have changed here. You don't want them to be the same as they were before.)
Now we're ready to bring those icons back into EQ2.
11. In EQ2 type /loadhotkeys hotkeys.txt
12. Those new icons should have popped up on your hotbar
13. Enable icon dragging from your hotbar by rightclicking the edge of the hotbar, choose "Hotbar Settings", and then click "Allow Draggable Icons"
14. Edit each macro and drag the corresponding icon from your hotbar to the macro edit window, overwriting the old macro icon in the upper right corner of that window.
15. Turn off icon dragging for that hotbar, if that's how you normally play.
We're just about done!
15. Drag each macro back to your hotbar.
16. Test them out to make sure they work.
17. Now, finally go back and edit each macro, delete the old step with a spell and drag the corresponding cure potion into the macro edit window.
That's it! You're done. The only drawback it that there's no shading to tell you when you can use the potion again and you can't see how many potions you have left. But alas, that's how all item macros work. So you probably already knew this.