Use indigenous plants rather than importing 'weeds'. Find out your local native grasses and use those instead. Lomandras are probably one type. Good to hold soil together as they apparently have shallow but strong roots. Adding drainage should also be included as would the hessian types of pervious mattings.

Is it a dwarf flowering gum or a big one? Many gums affect the ground beneath them, not allowing other plant competition to grow there...except azaleas, rhododendrons and other acid loving plants can do well. Another idea is to think of some native grasses, there are some excellent decorative cultivars now that are very hardy too. Some of the small lomandras could be planted in clumps of varying heights and colours, also dianella silver streak would be pretty.

I agree with the comments above as well. A garden with different types of grasses looks fabulous in a coastal environment. Your soil type may also impact what will grow best. I had trouble with planting out our front yard at our last property. I took a picture of the area I wanted to plant out to the local nursery and they were able to give me some really good advice of what sort of plants would survive. Also, decide what sort of garden you are after, e.g. low maintenance, native, colourful, or something you need to tend to. There are so many options, but deciding what you are after will make a huge difference in the type of plants you should get. Gallifrey your garden is beautiful, love those cute little green mounds!

Fabulous, love cloud pruning, very stylish, great article.