To start i would like to say that the original exploit came from: http://www.mmowned.com/forums/wow-exploits/207808-2-tracking-same-time.html
I take no credit for discovering the exploit, i simply made this small macro to make it easier to switch between tracking types quickly and thus, perform the exploit.
1. Open up your macro pane with /macro
2. Click create new then name and pick an icon for your macro
3. Type in /cast [Modifier:shift] (First tracking type here); (Second tracking type here)
Example : /cast [Modifier:shift] Find Herbs; Find Fish
4. Click (or press the key the macro is bound to) once then hold shift and click the macro again
5. Eventually you will get the both types of tracking at the same time!
Enjoy!