How I miss Moreton Bay here in Dubai! I grew up in the Redlands in Brissie and loved planting my 2 new gardens. You have a lovely sized block by the looks of things. How about deciding on some zones for functionality? Eg entrance/walkways, seating/rest area, areas of visual and/or textural interest. For example statement trees, water features, feature pots etc. I have always loved the effect of mass planting and tend to use clumping/propagating plants for cost effectiveness. If I had your place? A statement tree/two, a water feature, plenty of lush plants like Murraya Piniculata (orange blossom) hedge to cover fences and create boundaries/rooms. Also love liriope, agave, rhoeo (moses in the cradle), gingers, flap jacks, gardenia for scent, bird of paradise for big spaces and plants that are hardy and succulent or semi succulent. I did a whole planting scheme and layout including a dry river bed, a railway sleeper set in stones/ decorative grid pattern with a water bowl on top (which I found the "how to" in a magazine). So much work but so rewarding!! Create visual interest and ensure you have a place to stop, sit and enjoy! Good luck!!!

This is an idea that will increase the usable space. Place the plants on one side to create the height and depth as mentioned in a comment earlier and then draw the timber closer together in an area to have extra sitting area. Between the others place plants like native violet that will cope with the shade. With extra space on the timber you can now have room for planters on the concrete. Paint the fence dark if you want but you could just cover with plants as it looks dark enough. Creepers like native wisteria could work. Local nursery will help as mentioned.

Very pretty plant but keep in mind that it will most likely have a short flowering life. A fiddle Fig is very popular with great leaf shape and easy to manage, just plain green all year round. Mother Inlaws Tongue, Snake Plant is another popular easy to manage plant,

Start by spending a portion of your budget on the various dream feature items that are relocatable and can be used in your final design anyway. e.g. Buy the firepit you really want - it can become the focal point of your future garden. Test it outside in your backyard for a few months. Are heaps of mozzies annoying you while you're sitting outside around the firepit? If so, then you'll know that you're going to need a gazebo with flyscreens as well as privacy curtains so you can really enjoy lying outside in your hammock year round. The hammock is another relocatable part of your design. First, lie outside in your backyard on a swag or a rug for a few hours. Is it too windy? Is there road noise? Keep experimenting until you've found the perfect location for the hammock. Then buy an inexpensive hammock and suspend it from a couple of sturdy RL4 poles. If it's working, then this is the place where you should build your future patio, that's going to shelter your hammock. Keep testing inexpensive versions of your other ideas out. Trial tea candles or a string of inexpensive white Christmas lights as garden lighting. Do they create the feel you want or do lights just attract moths or unwanted insects? What about relocatable solar garden lights? Or a portable floodlight from Bunnings? Where's the ideal place for your garden table and chairs? Test it out with inexpensive camping chairs - or chairs you already own for a few months to be sure. Then invest in the perfect outdoor table and chairs. Same with the water feature. Start with a wine barrel with a waterlily or a second hand pond off Gumtree. Can you hear the trickling water in the garden or do other noises crowd it out? Keep in mind big goldfish need deep water and space to swim. To help you in your choice of plants,look around your immediate neighbourhood. What purple, blue and scented plants are thriving in your immediate area? Who has the best garden in your street in your opinion - and why do you think that? Do you always see a particular neighbour passionately working outside in their garden? That's the person you should strike up a conversation with to get advise about suitable plants for your immediate area. Chances are they will not only give you heaps of free advise but they will probably give you plants and cuttings as well. Markets are another source of perennial plants that grow well in the local area. Plant these smaller plants into large plastic pots and garden bags and allow them to grow for a year or so. Consider herbs as filler plants - many are highly scented, can be used in cooking and often have interesting foliage e.g. choc mint, fennel, rosemary etc. After you've been using your backyard for at least a year and you've experienced all of the seasons, then invest in your big ticket items like your gazebo. Buy or build a structure that's truly practical for your local microclimate - incorporate glass, windbreak fencing, shadecloth, mozzie mesh or whatever you need to make your hammock shelter ultra comfortable. Build this structure where you've tested it and know it will work - not where a stranger who designs gardens thinks it should go. Spend the remaining money on the things you know you need and want - the stones, plants, irrigation, a birdbath, etc