ASo I have been making cakes for about a year now and 100% self taught. I'm always learning something new everytime I plug my KitchenAid in! When is the right tim to"whisk" and the right time "beat". Cake batter, frostings, ganache, royal icing and ect.
For most regular cake batter, I would use the paddle/beater. The whisk attachment is for whipping a ton of air into whatever it is you're making. I very rarely use the whip. I use it for whipped cream and Italian meringue buttercream during the meringue phase. When I add the butter, I switch to the paddle attachment. I don't like too much air added in because then it's difficult to smooth. With ganache, I always make that by hand. If you want a whipped ganache then you could use the whisk. Hmm royal icing I'm pretty sure uses the whisk attachment. Most recipes will tell you.
I'm with Annie. I seldom used my wisk.
Referring to the KA Artisan manual: