Thanks Squizzy. I'm actually in the same boat as you most of the time and focus on the hardscaping aspects (limestone & paving) along with irrigation and turf installs.
I do a lot of work in conjunction with a garden designer who does use a lot of native plants. As it mostly residential the trees used are small trees only and the most commonly used are small gum trees like Eucalyptus caesia "Silver Princess"and other natives including Hymenosporum flavum(Native Frangipani)), Agonis flexuosa "After Dark" (Weeping peppermint with purple leaves) and native Blueberry Ash (Elaeocarpus reticulatus). Exotic trees used regularly include ornamental pears, plums etc.
A lot of native shrubs and groundcovers are used including lots of species (and named cultivars) of Grevillea, Westringia and Myoporum. Also native grasses/strappy leaves including Dianella and Liriope.
Smaller exotics include Convolvulus cneorum, Agapanthus sp, and Gardenia varieties.
We always need to do LOTS of soil improvement to deal with the gutless sand Squizzy mentioned which is everywhere....
There are a lot of West Australian natives that work really well in residential gardens but like Squizzy said above a lot of people are hesitant to use them for many reasons. There was a surge of "Australian Native Gardens" here many years ago and many people put plants in with no ongoing attention at all! "But they're drought resistant according to the tags"....
There was also very little pruning done so plants just went leggy and ugly. Properly maintained (and selected) a garden of local natives can provide magnificent flowers right through the year and bring native birds, lizards etc into the garden.
Some examples of my work can be seen on my website. This is pretty indicative of the kind of work regularly undertaken in Perth. Use of raised gardens and terracing to create interest through level changes. With (generally) small yards we find its a good way to get more from the space.
http://www.mrgreen.com.au/landscaping_1.htm
Cheers
Tony