Are you asking about a few potted plants, or a remodel?

Start planning to take your direction from Italianate style. Your home is headed that way, but lacks detail. A fountain out front would be beautiful. Consider painting in a beautiful warm Italian palette with some contrasting trim. Think about where you can add some more architectural details (around windows and arched entry, stone for the 'tower', etc.) I think you should get an architect involved. You are on the verge of something special.

I don't think it needs much at all. First of all, I think landscaping is like a wardrobe. Every few years it is time to go reevaluate and get rid of things that are not working. So I would trim back a bit, maybe remove some plants and especially simplify the bed in front of the tower. You have growing chives or society garlic. It is pretty but to my eye it is too bunchy and too tall. I would replace it with very low uniform ground cover. Thyme perhaps.

I'd like to see a metal pergola above that center window. If you could find something in wrought iron that would be nice. I just found this picture.

Then on that right corner plant a Bougainvillea.

To go along with that you could add a Juliet balcony to the window above. It is the spidery thing I tried to draw.

You house looks Mediterranean to me but your lights look a bit American Colonial. They aren't that bad but something larger and Italian looking.

oh, Juliet balconyYou have a tree that needs to have the canopy raised. Have an arborist look at it.

I would not add stone if you stay with the Spanish style look.

Are you painting the house off white?

I like your ideas. We haven't decided on a house cold yet.

I would suggest you get your tile roofing cleaned right after removing all plant material from your stucco. A good landscape plan is important to set the stage for your work on the house. I suggest you do some "photo" searches on Houzz and save pics of houses you like. Then sit down with a designer or architect if you plan substantial changes and develop a detailed plan. You can then implement the plan one phase at a time based on your financial capabilities. You have a great home so you can make it outstanding.