Hmm, difficult - less than four feet wide is the problem, so you'd be restricted to columnar shrubs or very small ones only. Is this the only garden you've got, or just an area of a larger garden, and what's the aspect? (meaning which way does it face, how much sun, shade)

10 yards by 1'10 yards/~11 square feet
roughly 9.5 metres by 1 metre/~9.5 square metres

Width is the issue. My first choice in a long-thin garden would be to make it look larger, so I would split it up into smaller chunks to elongate it visually and make it look tall, so lots of tall-thin plants mixed in.

Given that it is a very small space could you add an arbor or pergola to the site? You could train Wisteria, Clematis or roses (any climbing plant really) over it.

One way to make such a garden look bigger is to plant dark colored foliage or flowers toward the back, and light colors toward the front.