My house, built in 2003, has purple feature walls in the dining room and 2 bedrooms and green feature walls in 1 bedroom and 2 living areas. That was the fashion then. Recently I decided it's time for an update as the feature walls seem to be absorbing all the light and making the house very dark. So far I've undercoated 2 of the feature walls and what a difference it makes! The rooms are much lighter and now I have to decide on whether to add a lighter colour as feature walls or paint them the same colour as the rest of the room.

If time and budget permit I would add horizontal screens (timber stain or charcoal/woodland grey) from the right pillar to the garage (hiding the down pipe) and from the left corner of the house (hiding the bins) Do basic landscaping, two narrow beds either side under the windows, bark mulch and simple plants e.g. Lomandra longifolia (a native low grassy dark green clumping plant) is common but easy spaced every 30 cm Valuers like safe and neutral schemes, so keep with the Woodland grey roof/fascia & Classic cream garage door and repeat this on the upper feature slats for now. Then add a warm complimentary colour for the front door, this is Dulux Rodham Then get a lush new plant for that pot too. If you keep it simple (KISS Principle) for now it will come together for sure :)

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,

None of the suggestions so far, hit your brief which was for a lush tropical vibe. Nearly all the plants suggested are for temperate gardens. To create the tropical vibe it's all about the leaves. Luckily you have the perfect orientation for just such a garden. Here's my pics. Along the top of your retaining wall plant Alocasia, otherwise known as elephant ears. These are essential in a tropical garden as you need big leaves for a lush look. Alocasia come in many varieties and lots of different colours. Choose the one you like best. They grow in part sun, but can tolerate short full sun hours and nothing looks as tropical as these babies. Alocasia do send out runners so if you don't want them spreading up there you can pot them up as pictured. Putting these up high will create a canopy-like feel of big jungle leaves. Next you need smaller leaves and colour, enter an Indonesian tropical plant that is very popular but in your climate will do best with only morning sun. Croton. These are everywhere in QLD and other subtropical gardens. They are slow growing so you never need to trim them and top out under 2 meters high. They have the best colour when planted under taller plants where they receive dappled light for short hours of the day. Too much sun and their leaves bleach. They come in many different varieties, many colours and leaf shapes. They are a beautiful low maintenance plant. Croton do great as a potted plant as well. It's not a tropical garden without a water feature. I favour still water features which are simple to put together. The most expensive part will be the glazed bowl which depending on size can run about $200 but it's a one off investment. One of these with either a water lily (not lotus it's too big) or a papyrus, throw in some frogbit which is a floating water plant and you'll have this.... As long as the bowl is less than 30cm deep you won't need council approval or a pool fence. This particular bowl is growing a sedge (tall grassy stuff) arrowhead (the triangular upright leaves, you can eat the bulbs) a small water lily and a canna. Perfect for a tropical vibe. For something to cascade over the edge I'd avoid the Dichondra silver falls pictured in other answers. They create a dry climate rather than tropical look. Great tropical cascaders include... Syngonium, you can get this at any garden centre or take a drive around local parks it's often growing wild as a garden escapee. It's very easy to strike. Just pull of a section with a bit of root attached and stick it in your ground. Hoya, or wax vine. Few things look as tropical. Also very common in garden centres. Or another option is to grow this native, DIanella silverstreak all along that retaining wall and let is cascade over the edge. It grows full sun to part shade. It's easy to buy in bulk for a mass planting. Once you've got the big stuff planted up, you'll have patches of sun and shade that you should fill with creepers and other low growing plants that take your fancy. Silver Lady ferns are hardy and look great in a shady spot. You cannot go past a birds nest either as they famously take even full sun without burning. This ones growing with caladiums (miniature type of elephant ear in very colourful variations and a grass. While single plant mass plantings look great around hotels and public parks. A backyard is much more interesting if you mix up the plantings with carefully chosen combinations that create height, big leaf drama, colour and texture. Tropical gardens can be very cool. Look at all the different heights, leaf colours and textures here. Creating the tropical look is about creating a canopy effect with some tall plants, big leaves, coloured leaves and creepers. PS - Forget about bamboo. Someone planted 20 clumps of the stuff in my garden, it's ugly and impossible to remove as the rhizomes are like concrete and need a bobcat to dig out. What people don't tell you about clumping bamboo is that the clumps continue to get larger and larger taking over your garden. It also regularly goes through periods of looking awful.