I tend to go for symmetry. For me, that ties things together and makes your potager look intentional. Perhaps a large pot of edibles in the center and make triangular wedges radiating out from that as your beds. You could define your beds with an edging of alyssum, marigolds, pansies, violas, or lettuces.

If you want to get rid of the mystery ground cover, you could lay down several sheets of damp newspaper covered over by either your planting soil or a mulch to define paths.

A little bench back by your boardwalk would be a great place to view your garden too.

I forgot to mention that this is all being done over the root system of a 30 year old maple I had to remove 2 years ago. The pot on the right is where the tree was and the base of the trunk is, so I can't grow anything there and it really throws off attempts at symmetry. In the couple days since I posted, I decided I might just keep this ground cover.

I also ordered the planter/feeder/light deal I linked below to put in the garden. It's probably way cheap quality, but at worst, it'll show us how to build a nicer one.

Here is a link that might be useful: Birdfeeder planter

pyxiwulf,
I have a front yard potager, although larger than yours, it was also over the site of an old maple. The maple roots continued to grow after a tornado split it in to and it was ground out by the stump. So we decided with that, and the clay soil we were putting in raised beds. Worked like a charm. We mulched heavily over the non-planted areas as walkways and that has eventually killed out the root system so it no longer invades the beds.
I personally didn't worry about exact symmetry but balance of the eye mixed with maximizing growing space. Mine is still not maximum (I learned I can live with less space between each bed, and am not married to the idea of having square or rectangular beds....)
I guess what I am saying is try and see what works this year, and if you don't like something it's so easy to change. I absolutely agree with having something look purposeful and organized especially in the front yard. It will help people to accept the idea that a front yard garden with vegetables can be as beautiful as it is functional!

Yeah, I think my desire for something adding some structure is for the non-growing season mostly. When everything is in full-bloom or fruiting, the garden is beautiful, but from late fall, to early spring, it's not very attractive, kind of looking like it's a mess. Hard for people to envision that it's got something going on in the growing season. Which can't be good for property values :D But I think with the stone borders and some other non-plant type things going on, it will look like a dormant garden and not an unkempt plot of dirt, you know?

Sadly it got pretty cold here this weekend, and I haven't been able to do anything more to it in the last week. I'm so anxious to get more going on, it needs to warm up again!

There are some things you can still grow in the winter.
Chard, lettuces, broccoli,etc..then there are the ornamental cabbages etc to spruce things up. Just a thought.

Yes, where are you gardening? You have zone 7...potentially in zone 7 you can be winter gardening in all 4 seasons depending on your snow cover. Nancyjane is right, there are many lettuces tolerant to cold temps. Look at the Fedco catalog. They list at least two lettuces cold hardy in Maine. Then there are mustard greens in both green and burgundy leaves, Champion Vates collard greens are cold tolerant, so are many chicory varieties, kale are all very cold tolerant and come in reds, blues, various stem colors...swiss chard is in rainbow colors, pansies can bloom much of the winter..it's quite amazing what can work for you! For structure you could have almost anything at all that provides "something"...tee pees of bamboo, metal oblisks that you can grow peas or beans on during the summer, wooden oblisks....you can put lights on them for the holidays!

Another thing to think of using is large eye catching pots that can serve as structural art for the eye or to pull the eyes at whatever you want as a focus point. You could plant seasonal type annuals in it and rotate them out-ex for shade begonias, impations, coleus...
Check your local area for plants that do well in the shade. If you work with the conditions as they are, it is easier and a lot less work to pull togather a cohesive pleasing garden for you and your site.