John you are fortunate to have such a yard, although the tennis court does aspect as a divider breaking up the space, I think this creates an opportunity to create garden zones or rooms. Intimate garden spaces can be individual enough and still be integrated into a larger footprint. Your garden perhaps may be viewed from different windows, and have different aspects, therefore will have different requiremnts of sun, shelter etc. As the second picture appears to have a shed or structure, and looks more of a utility space, I would obstruct the view from the court, by planting a Boston ivy to cover the fencing, providing a delicate hanging foliage wi ever changing colours of reds and greens. I would do the same on the opposite fencing that overlooks the main lawn area, although I would create a large window effect by clipping or restraining the creeper from a large square in the centre fencing section. Tis will create a room with a view in the foreground, and with effective and clever planting, lighting and design elements, you will create an interesting viewpoint that will direct interest into the yard beyond the court. In the background, the timber fence I would plant your murray a hedge, so the small blooms will soften the look of the fence, paint it a dark colour, like domino by dulux so the foliage stands out against it, and gives an illusion of a deeper boundary. In front of that, centre to your created window in your fencing, place either a sculptural element, in the form of an urn, a formal topiary or statue, perhaps a small water feature with lighting, so it extends the perspective yet again. With the green hedges now creating the walls of your garden room, plant your chosen iceberg roses in front of that, and some informal plantings below. I suggest a bench to watch a match or two, and utilize the other garden Rea to house things such as your patio furniture. Garden rooms don't necessarily make a space smaller, rather they may invite you to meander through garden rooms with beautiful elements and relaxing places to sit. I would also like the look of manchurian pear trees along the fencing if you don't like the idea of a creeper.

Go light, can you manage a window box? inside would do. Im assuming that you are not tied to a kitchen sink so the windows main purpose is to let light into the room, Herbs flowers bulbs even stained glass panels can all add interest

The rendered brick wall is on the property boundary and is the neighbours garage. With the wood screening I was thinking to finish the height similar to the rendered brick wall. The stoned area at the end of the deck is just under 3 meters deep and the trees are 1.5meters in from the back fence. I would like to keep the one closest to the wall if it worked in but not fussed about the other two.

Absolutely agree about hedge... Leave it but have it trimmed and add trees to courtyard. I would decide on colour scheme first by painting large pieces of cardboard in a colour suite to complement the brick. Draw out lighter colours in brick & tone down with white to match look.... I would not personally use white paint as your brick is so dark.... Think cohesion not contrast... Ideas above re gate, letterbox, etc are excellent and another way to add interest... Also think about changing driveway colour to match house/garden as it is a big slab of grey... Your roof is dominant too...... Maybe get that done rather than rendering house walls.... I would look on houzz for ideas.... Look up Prairie style or Frank Lloyd Wright or Fallingwater his most famous house for colour/style ideas.... Or Taliesin West for anchoring house into land innovatively. Paint that chimney flue to hide it!!!!!!