Let's start the process with Design.
When we started out many years ago the option was basically pen & ink, with electric erasers, rotring pens , large drawing boards, dyeline printers and photocopiers.
Today we have any number of CAD programs, with designers using combinations of hand finishing, photo-realistic renditions, 3D imaging and videos. All have a place, however apart from basic landscaping the final design is still very much the preserve of the creative designer, all that's changed is the method to present his creations, the time it takes to reach this point and most importantly the material quantities required, this makes pricing much much easier.
From small intimate, highly detailed spaces :-
To Mini-Estates, covering many acres...
Design requires a knowledge of soils, conditions,materials,construction techniques, problem solving,building practises, plants,most importantly clients likes & dislikes all mixed with creativity, flair & experience.
Results can be truly wonderful :-
From this simple Mediterranean garden requiring almost no aftercare
To this much larger estate.
or this rather more complicated roof garden complete reconstruction, with access from a smoke vent...