There is much that is very attractive in your backyard and your house has very good lines. You start with "good stuff." That is a plus for you.

I'm glad to hear you will be modifying the pool surround. I think concrete (with some decorative texture) will look better than the tiles and you need a lot more deck space.

Right now, your two lounges hardly have room to fit on the tile. More concrete and you could add a couple or three very large planters and more seating area.

You could possibly use some privacy plantings in the yard--make your yard cozier and appear more secluded. You could also use plants to hide pool utilities, if you changed the concrete sidewalk location. Plant in front of that shed (I think a shed) to soften how it looks.

Plant in layers: taller in back -- then medium height--- then low. Will give your eye some depth to look at.

It appears you live in a climate where things will grow quickly. Don't overplant. Plants WiLL get larger!

I agree---plants with color will pull together a stunning look for you.

Good luck with your planning and your project! …..Put lots of thought into it and it will be a very successful endeavor!