Ours needed a lot of effort to spruce it up to even acceptable standards, so this is what we did (and are still doing!):
Jet wash patio and paths
Paint fence with watered down bleach to remove green algae type substances
Bought lots of pots for the patio which all have the same finish but are different sizes and heights - I am refreshing them at the moment and will be putting in dianthus pink kisses, purple and white violas, a white chrysanthemum, some late flowering salvias (Amistad, I think), some asters and saxifrage Shiranami. All of these have been chosen as they are really long flowering. I can see them from the house too. With pots I would say that a bigger pot or two (or three) make more impact than lots of smaller pots.
Bought climbers for height and more upright interest whilst the shrubs establish. The jasmine, clematis montana and upright ceanothus have been great this year.
Also bought some pretty painted bird boxes and insect houses for the fence.
You seem to have done loads already though. What about:
Some garden art type things? I see lots of mirrors, metal 'pictures' (sorry, I don't know what to call them as we don't have them), but I see that you've put a mirror.
Do you have space to plant an established tree? Instant impact. Ornamental or fruit. I love flowering cherries and magnolias.
What about an archway? Maybe to create a quieter place in the garden, and sort of invite you through. You could have climbers on this like a mix of roses and clematis. There are some very long flowering and fast growing climbing roses.
Would the budget extend to new garden furniture? Maybe a swing or a bench if not the full works.