The Boy Scout approach
Be prepared. I never raise my voice except to be better heard over wind or motor. I've been told that I convey great confidence to new guests or nonsailors because no matter what happens I am calm and seem to know what to do. Without giving numerous examples over 40 years of sailing in boats from 14' to 132', I can just say it's all due to preparation. I study and reread the authoritative books to keep refreshed. Mentally I imagine the feeling, and visualize what kind of things can go wrong, from misunderstood orders to the vagaries of unusual weather or anchoring conditions. I develop a plan A,and a plan B for equipment failure or misjudgement on my own part. I maintain the boat for heavy weather or deep sea conditions though I will probably not endure them but once every 20 years or so because of weather forecast knowledge.When we go onboard,I explain to the crew and guests that sailing is an adventure. No one can really tell in advance what might happen on a one hour, much less an overnight cruise. I explain that there many techniques and approaches to sailing and handling a boat safely and successfully. I will choose what I think is best for safety and comfort, but I'm always open to hear their opinion, though it may not affect my choice of actions. I take responsibility for all that happens on the boat whether in dock or under way.I remind the crew that I will occasionally make mistakes of timing or judgement and will readily admit them. They are always welcome to question my decisions or ask how or why things work the way they do.I try to get everyone on board involved in some way. I explain, well in advance of they are needed, what I'd like them to do, when and how. I get them to tighten a line, or coil a rope, arrange the life vests. I especiallly want everyone, man, woman or child to man the helm for a shortwhile while I go "check on something". (Usually to lie down on the V berth, close my eyes and listen to the sound of water swishing by the stem for one minute) From 7 to 70 yrs of age, every nonsailor gets to feel the great joy and magic on controling a boat under full sail. My great joy is sharing my time on the water in a quet, harmonious and peaceful way, regardless of the "adventure surprises' that can befall a sailor while sailing under canvas or iron wind.I never lack for crew or guests. And I'm still married to the same first mate I started out with 45 years ago, so I think the above works for me. Might work for you too, regardless of what choices you've made in the past.