^ Yes don't let a chef hear you say it, but 95% of commercial catering only needs you to follow instructions and use a bit of common sense.
The 'Top of the Range'are those chefs that have to create their own recipes and get them accepted, but in most places you never do that.
And dishes are much easier than you think. I'd heard stories about people not being able to make yorkshires so never bothered until one day I thought I'd give it a bash. Easy as anything. I don't understand how people get it wrong.
^ That should work as long as the oven is ready and really hot.
Mainly that as you have to heat the oven you may as well heat the tins/oil at the same time.
Don't do it on the hob as won't get a uniform heat, it needs to be in the oven. Ideally when you pour the batter into the tins, the oil will sizzle and the batter will set at the edges.
Best way if you have time is to make the batter and let it stand for 1/2 an hour or so then give it a final whisk to ensure there is air in it just before you use it.