First, here is the whole MOC:
Pool Party by eilonwy77, on Flickr
Here's the first page of the tree tutorial:
Tree Tutorial by eilonwy77, on Flickr
If you leave the leaves woven for a while, the branches do come out a little bent, but they seem to bend back into the proper shape fairly easily.
Here's how to do the wall:
Curved Wall Technique by eilonwy77, on Flickr
The pool deck floor is done by squishing lots of round 1x1 bricks (each covered with 2 round 1x1 plates) together into a hexagonal grid. (It's the same idea used for cheese slope mosaics: squish the pieces together, fill in the gaps, and if you get the tension right, it will be fairly solid). You can see other examples of how this is done in this set. Truth be told, getting this done in this case was a nightmare. It took forever, had to be redone lots of times, and caused me all sorts of headaches. I can't say that I recommend it.
Happy building!
If you need any help, let me know, and I could try to help. 
