I would move the swing to the side of the lawn and move the chairs to the rounded area, so you can truly enjoy the garden vs being on cement under a deck and then add a small fire unit for the cold evenings and Turkish shawls over the back of each chair. You could add some solar lanterns in the garden (which will be enjoyed from the top deck as well), which will warm up the whole yard. Your tea lights could be hung on the rafters under the deck and you could add a table and chairs there so you can eat outside.

Looks like San Francisco to me!

Yeah, I'd make the cobblestone patio the primary sitting area, with a fire pit if you think you'll use it regularly. Create a destination to draw people off the deck into the back of the yard. Move the swing elsewhere -- on or under the deck, maybe. Or Craig's List. I'd keep the area under the deck simple, with a couple of chairs, or a small cafe set, or a hammock if you're a napper. Some colorful pots with vines trained up the deck posts could be cool. I love glazed pots.

I'd add some pots with small shrubs or trees in the garden area as well. Maybe some garden art. Look for low-growing evergreen ground covers for your planting beds to make them more lush. How about a patio-sized tree (or two) behind the patio and/or along the side? I love trees.

Very nice space, BTW. Enjoy.

Your yard looks like you are making a great start! I would use some up-lights behind some of the shrubs along the fence and especially in the corners.