This is the story of one small, forlorn spot in a garden, and how it became an effective composition, over a month's time, in a client's garden.  It's a "before and after," with all the steps between.

How to:

1.)  First, start with an area in need of attention.  

Background and parameters of the spot I am writing of today:
It's a small blank area to the left side of garage door. The driveway has been converted to a garden. The space is constrained by property line (the space I have to work with is maybe 3' deep). The side yard is "shared" (no fence down middle). A big blank wall and awkward angles of existing fence (on neighbor's property) form the backdrop.  

This particular area was calling out for a focal point, as it has a direct site line from the back yard. When you move through the garden, you frequently come face to face with this spot. When we started, it was an ugly spot.

2.)  Stew for some time about the existing "stuff,", puzzle over solutions, and help the client to "let go."  

Reasons for stewing in this particular case: Weeping Blue Atlas Cedar dominates the spot; its huge trunk is beginning to crack the pot; client doesn't like the plant much, but it was a gift from a friend when client's father passed away.  Problem: client guilt for killing a plant and for a gift that held meaning (even thought they were not fond of the plant).

Solution: the Cedar finally broke its own pot, with roots that had become huge and wrapped around itself. Unsalvagable. Decision made.

3.) Create a blank slate.

Remove some unnecessary plants and overgrowth, and keep the desired structural plants. In this project, note that some of the plants are on neighbor's side. We were able to edit out some of the worst offenders contributing to a chaotic feeling.

4.) Find an element for the foundation of vignette.

In this case, we chose a small wire bench that the homeowners already owned.  
We had been trying to use it in other locations, but everywhere it was too small...

...We moved it to the little area at the garage door, and there its proportions were good with the surroundings.  Although it was the only thing yet in place, it felt right there.

5.) Add infrastructure where needed. 

We added a gravel landing spot for the bench.  Although there is no photo of this step, it is one of the steps that takes some material and labor, and was important to the establishment of a new purpose for the area.  We excavated 4" deep, relocated excavated soil to other part of garden, used quarter-minus crushed stone (same as existing pathway) and compacted it.

6.) Find some cool art that fits the space.

I feel very fortunate to have found James Merrigan and the screens he builds for his business Garden Art by James.  If you are also donating your time and garden to a local Open Garden fundraiser, as we were in this case, you may have the opportunity to ask a local craftsperson to be the featured artist in your show. I asked James, and he accepted!

7.) Collaborate with artist when you can!

I visited James' shop and we selected several screen options to use in this client's garden.  On the day he brought the screens on site, we tried this one behind the little bench.  This location immediately grew on everyone.

8.) Fill in with proportionate elements as needed.

Our space needed containers.  Tip for container selection: try samples on site, such as spare big black nursery containers--even empty boxes--anything to put on the ground and determine the right scale of the future containers.
By this method we determined the need for one ~16" x ~16" container, and one upright. Then went shopping. The hard part about shopping is now you also must make decisions about form and color and texture...etc. It can get quite complicated, but your trying size examples first will help a lot. 

When shopping, use measurements (or your hand when you forget your measuring tape!). I know that two of my hand widths = 16".  If you use photos while shopping, put something in the photo for scale.  In choosing containers, scale is everything!

We found our containers. This homeowner prefers simple pots, and plants that carry the show, instead of the container.  We chose lightweight resin containers, which can make a gardener's life much easier in the long run. The upright form was very helpful in this narrow space.

9.)  Choose plants

Our little composition needed height, as well as plants able to take the hot sun and life in a container.  I found these Staghorn Sumac (Rhus typina 'Laciniata') at the nursery and knew they would fit the bill.  Took photos to work out the combinations and heights (using heights in triangles, for example, is a good design tip--but that is a topic for another day).  Brought two Sumac back to the site to try in the pots.

10.) Plant the containers.

If a 100-degree day is forecast on the weekend before your Open Garden, and you must plant your containers that very day...hang shade cloth!

11.) Enjoy!