Ikea are doing some very up to date hanging planters at the moment, which look better than the old style macramé ones in my opinion. The beauty of them is that you can fill your windows on a greater scale than by just using the sills. That said I only have a little cactus pot and an orchid trough with an orchid and gardenia in it myself as I still haven't been to Ikea and only use the kitchen window due to kids' messing potential elsewhere

Is there drainage in the brick bed? I would also go for lavender. I'm not green fingered at all so I know it doesn't particularly like clay soil (I had to replace half of mine each year) but I don't think it requires much soil or maintenance. Does the bench fit under the bathroom (?) window? Just thinking its a shame to cover up the stone beneath the window. I'd paint the bench a grey with a purple undertone. I think the lavender will look lovely against the green garage and door and gravel to give a Mediterranean look so I'd also go for an olive in front of the drainpipe. I might also paint the meter box in a warm grey to blend with the brick and have the blue pot in front of that, Rachel's geraniums sound good. Perhaps buy 2 terracotta pots and have 3 pots the other side of differing heights. Perhaps repeat the geranium, then rosemary and a windmill palm (I think these will grow in pots and in the shadier area, hopefully one of the others will correct me if not!)

What a nice design, I especially like the small border next to the patio, looks like a flowing stream almost. Will you be taking up the gravel/slate chips in order to plant things or planting through it? If keeping gravel then I imagine there is a weed membrane beneath so you’ll need to cut holes so plants can access the soil beneath. I’m no expert but for plants there are lots of choices. When choosing look on labels or web info for their eventual height and spread, sun aspect (wether it likes full sun/shade etc.), soil conditions, hardiness, and so on. So in your garden, areas 1 & 6 are north facing so I imagine it would get very little sun so plants like fatsia japonica, hostas, ferns, bergenia, which perfer shade would do well. There’s many more. There a website appropriately called Plants for Shade with lots of ideas. Area 2 & 3 by the back fence are you thinking a dense shrub to completely cover the fence or a sort of hedge higher up with ground cover underneath. If the latter have a look at standard or pleached trees/shrubs (I call them lollipop trees). I find red robin a little loose and airy but the red tips are nice. This site has some good ideas for standards: https://www.paramountplants.co.uk/clear-stem-trees.html For ground cover or front plants, lots to choose from. Hardy geraniums are a good all rounder, dies back in winter and needs a trim but otherwise no bother. Area 4. Both choices are lovely and there are lots of acer varieties. I do like the look of the Viburnum Mariesii tho....I’d go for that. Area 5. Buxux can sometimes suffer with box blight. There‘s alternatives like ilex crenata and certain varieties of pittosporum and eunonymous which could work. Personally I’d go for something a little less formal. Maybe something that forms neat little mounds. Alpine plants and small sedums perhaps. Too many to name but I have a saxifrage ‘Peter pan‘ which is a clumpy evergreen and thrift which does well in a confined sunny space. Small ornamental grasses would also work well. I noticed in your other post asking what plants for around the water feature. Besides the shade loving plants mentioned how about canna lillies in tall pots. They’re quite tender and need a good amount of TLC but a stunning statement. Would also compliment the bamboo (in separate containers) if you wanted it. If you like the tropical look this might give you some ideas as well: https://www.gardenersworld.com/plants/plants-for-a-jungle-style-border/ Sorry for waffling on. Hope this helps. canna lily

Adding some greenery to the empty corner could indeed help soften the expanse of tile and stone, creating a more inviting and balanced outdoor space. You might also consider some permanent fixtures like a small statue or a wind-resistant shrub that ties in with the existing Myrtus planter if you don't want to opt for a larger, heavier pot. For the area on the right at the top, since it also appears quite bare and has an olive tree nearby, perhaps a couple of matching pots or as Isla said, a bench or some seating could unify the space and provide both aesthetic appeal and functional seating.