A couple of things I like to do, besides the obvious of having a buffet table for each type of food, is having different shifts for the bars, food stands and reception desks. No one wants to deal with a Sim who's been at the desk for 24 hours.
I've tried that on a few of the resorts I've built and it didn't turn out too well. I decided to make 3 of each service object... food stands, bars, front counters and set them all on a different shift, so only one is open of each object per shift. What ended up happening is clusters of people standing around blocking doors and paths. I ended up having to switch back to 1 of each service object, and to keep complaints from coming in, I had to keep them on 24/7... but since they don't appear to need sleep, food or showers, as unrealistic as it is, I left them there.
Attempting to stack towers one floor above each other failed for me, due to the intersecting object issue. I was unable to stack 2 Eco Towers above each other, yet I was able to stack 2 of the Beach Resort Tower's on top of each other. Cover the ground floor with Beach Resort Towers, then create a floor above them. You will be able to create an equal number of Beach Resort Towers above them. Then, just place all amenities underground.
In the space that an Eco Tower takes up, providing, at full upgrade, a capacity of only 70... I was able to stack 4 Beach Resort Towers, providing a capacity of 160.