After a while, when you are doing dishes you are comfortable with, you won't be nervous. When I am cooking Cajun or grilling something or doing fish, I never give it a thought. My sous chef did all the bakeing and veggies. I would never consider doing a big meal without her. Between she and her daughter and myself, we could handle up to 300 with a couple or wait staff. I can do up to 30 by myself. After that, you need some help. Always remember, you can sub contract some of the work on a big job. I helped on a feed for 1200 and there four different caterers working and it went fine.
We will never do it again due to health reasons but we enjoyed it and it can be pretty lucrative. I never wanted to do it for a living because it is dam sure work but I would do a few jobs a year and helped on a few. I enjoy cooking but now that my sense of taste is gone, it is tough.
I like doing a couple "backyard" things a year and always do a Cajun feast, feed a dozen or so. Since neither Donna or I work from recipes, it is always fun cooking with her and our guests are entertained by watching our byplay. She is mean as snake when she starts cooking :)