If guys like John Corriea (Youtbuer/Active Self Protection) are to be believed, then the cell phone always goes your weak side front pocket so that you can call 911 without breaking your shooting grip on your sidearm. Sidearm goes on the strong side belt. (Corriea is big on appendix cary-I am definitely not.) He, and others, will also say if you're going to carry a gun, carry a less than lethal option (pepper spray). Then you've got at least one spare mag if you carry an autoloader, if only to have another mag if your primary mag in the gun fails. Then you've got your keys and whatever else you carry. Sidearm and magazine can go on a good belt under your sport coat. Where do you carry your pepper spray? Add to that a pocket knife. What about a flashlight? Dockers only have so many pockets.