There really aren't any secrets. Once again, I'd like to reiterate. You can't control the texture of your mousse if you're not familiar with the texture of whipped cream. Consider the following made up example of a dessert which may cause a stir when served.
Trio of chocolate desserts: Bittersweet Chocolate Mousse Tart, Terrine of Foxpoint Vanilla Genoise Cake and Gianduja Ganache, and Chocolate Sorbet in a Florentine Tuile, served with Raspberry Coulis and White Chocolate Creme Anglais.
You know what this is? Leftovers. Yeah, I kid you not. Okay, to a point, but they're really good leftovers. Someone has some extra ganache and cake laying around, they cut it up and make a terrine. Whip some cream and make it into a mousse and pipe it into those tart shells you made for crab salad but didn't use. (wrong kind of shells but it'll work) Chocolate Sorbet maybe you were going to make anyway, some simple syrup and cocoa powder. Go steal a bunch of florentine tuiles from banquets and scoop it after it's done.
Buzz up some raspberries with sugar, strain, and add some white chocolate to yesterday's creme anglais. Mint and fresh berry garnish optional.
Even if you made it from scratch, that is, without leftovers. There's a basic recipe for the cake, basic recipe for the ganache, basic recipe for the mousse, basic recipe for the sorbet, basic recipe for the florentines. So, my notes for this might be something like:
Make sponge and ganache today, save half ganache for mousse, make tart shells.
Tomorrow before service make mousse, make sorbet, make florentines, (use less almonds this time)
My point is, these are all very very basic things which should be right there in your head. Maybe not the proportions, but all you have to do is yell and hopefully someone will say something like 1-1-1 and you'll be on your way. It takes no time at all to do things like that. It's the way it's put together and the process which is tough to learn.