(this is verbiage from our BERT training course)
In the ICS system you don’t want more than five people reporting to you. Three to five is ideal, seven max. The less people you have coming to you, the less chance you’re going to have of making mistakes or the stress that’s on you. If you have 10 people talking to you, you cannot keep all those thoughts in your head, you just can’t. You want to keep a manageable span of control of those people.
Use common terminology. Don’t use huge words or 10-codes or technical terms. In the Coast Guard, for instance, a conning officer will tell the person on the helm, “Come left 10-degrees”. It is too critical of a command to perhaps have that one-second delay of translating “port’ and “starboard”. Keep it simple.
If you’re sending somebody over to Building A, just send them with a simple mission or purpose and report back. Don’t tell them how to “build a watch,” just give the time.
Keep it simple; don’t get in long, drawn-out conversations; remember a lot of things that you do are time sensitive but don’t rush to make it a snap decision unless you have to.