I love the spiral idea! However all my herbs are scattered in a big bed. Although I wish I'd done a plan first as some of my markers have disappeared so it's an educated guess to what some of them are...also some of my thyme is fairly slow growing and I've got to remember it's there when I weed!
I went to the garden centre and just bought all the herbs I didn't already have
One I love is feverfew as I like the flowers though some people have told me it smells bad but I've never noticed that! Also fennel will self-seed quite happily and spread at least 4' away from the original plant! Although those little seedlings you can always pick and dry