I work with a marching band, and we want to use fog machines for a particular part of the show. I know how to code/program in Arduino, however I am not great in the electrical and technical end. I own two fog machines, and the issue is that we need them to start fogging on command without delay (at least not a long delay, just not early and not late). We cannot exactly stop the show in the middle of a competition to say "wait, the fog is coming soon." We also need them to stop fogging on command.
I have read this article, Motion Triggered Fog Machine and it seems simple enough, however, I do not need or want it to work with a motion sensor. I suppose the easiest way you could help me is to either point me to a tutorial or tell me how to modify that tutorial to my own needs.

we need them to start fogging on command; Where do the commands come from. A human pressing a button? A PC running some software? DMX controller? Smartphone? Without some additional info, we can't add anything that isn't already in the instructable you mentioned.