I've made them--they've been around for ages.
The pre-custom housing one:
Make a square of benches leaving a space in the middle. Fill the empty corner of these squares with lanterns with bucklers on top.
For the water:
Carpet tiles dyed blue. (I use the swirly ochre tiles). You could also use blue goza mats or blue cloth. I used cloth, since when I made the hot tub there were no carpet tiles. You will also need a couple of bales of cotton dyed light blue and some spiders' silk.
Place the cotton & spider's silk first, lock it down and raise it into a position in the middle of the hot tub. This is your foam and bubbles.
Now place the carpet tiles. If you need to raise the tiles place them on stacks of bandages.
I locked down a lump of wax & a bundle of flax on the benches--this looks like soap & a bath brush. I also locked some plain colored goza mats around the tub to look like reed matting.
If you use cloth for the water, your character will be able to walk through it and give the impression that he or she is wading. This is a great effect. Don't forget your swimsuit.
Some notes on using cloth for water:
To get the right look you will need to use 2 stacks of 2 pieces of cloth for each square of water.
To get rid of the cloth look, dye some fleece (2 per square) to go on top of the cloth. Work from the top down, placing the fleece and raise it. This can be a bit fiddly, but it does get you water you can sit on.