Planning your cluster doesn’t have to be overly complicated, but you should think through what you are trying to accomplish by setting up a cluster.
Remain in contact with people in your neighborhood during a grid outage.
If you are primarily standing up a cluster to remain in contact with others in your neighborhood during a grid outage, you may want one or more of the neighbors to add a node with a good roof-mounted omnidirectional antenna, that other nearby devices can make use of. For devices that remain out of range, additional node(s) may be added that are reachable by the main antenna. The possibilities are endless, but essentially you may want to consider having a few scattered nodes that remain in constant connectivity with one another.
If you are preparing for a grid outage, you will also want to consider power. ChatterBoxes and nodes don’t use much power, but obviously they do use some and can’t run forever. You will probably want to consider a battery backup power source that can be charged via solar or some other means. In fact, you may want to have your node running of this power source 24/7 now, so if the power goes off, you already know it’s solid.
Securely communicate with only trusted individuals while on the move.
In this scenario, maybe you are vacationing or hiking. Some things to consider might be clipping a node to your backpack or placing one in your car near a window. If you happen to pass over a hill, you may even want to leave a node in that high spot (check with and comply with local laws, of course). That left-behind node can function as a makeshift cell tower for your group, and since it has GPS on board, as long as your batteries are good, you’ll be able to find a way back to that point. Even if the node’s battery dies, once your other ChatterBoxes have gotten a ping of its location one time, they will not forget it.