I'm pretty new to S8 games but have been playing the restaurant stuff pretty obsessively. I actually thought this was the best special event I've experienced so far and was surprised that so many people had trouble. I've done the St. Patrick and Easter events (I found the first one difficult and not very fun and the second was easier but still not very fun). I'm level 32 now and went up a few levels during the event and I have 80 pantry space and managed to get Luana with a couple hours to spare having spent all the quickserves won from previous days and about 80 gems. I liked getting to work on a variety of recipes and getting prizes for completing a day. If I used any tactics it was only to refresh orders that needed an appliance I was using and I spent most of my gems on restocking after no luck with the market. I think the only problem was asking for orders that you haven't learned yet, but that only happened to me once. I think the previous events I played were too dependent on luck or took too much time but this event seemed the most balanced to me, and the most interesting.
I've also gotten lucky with Luana and recieved 10 gems for the first tip and 2000 coins for the second