The term triclinium can denote the dining room itself which regularly contained three sofas, but also such a permanent outdoor installation, as has been found, for instance, in Pompeii:

(This example is from Pompeii in Pictures).
So, the first step is to construct the centerpiece of the scene:




A little test with the figures (in a later post, I will list the stuff to be used):


The triclinium will be surrounded by a garden with hedges and a water basin. In order to get all measurements right, to decide how big the base plate has to be, and to prevent running out of hedges, I made a detailed plan using a vector graphics program (the first time, as far as I remember, that I really tried to plan the whole layout to the millimeter in advance):

The water basin will be made using acrylic glass. And of course, there have to be some statues and fountains to add the necessary luxury:


