Creating your own floral arrangement from supermarket flowers can save you a lot of money. The flowers for the arrangement in this project, which I bought at Trader Joe’s, cost only about $20, and the glass vase from Michael’s was less than $3. Yet the finished arrangement could easily retail for $80 to $100 — or even more — at a florist.

If the thought of putting together your own floral arrangement scares you, don’t worry, it’s pretty easy. I learned by sticking my fingers into arrangements florists delivered to the office where I used to work, to analyze how they were assembled. I’ve also had the privilege of working with several top-notch florists in Los Angeles, who have shared their tricks of the trade with me. They swore me to secrecy, so, naturally, I’m passing these tips on to you.

Get the right proportions

 One secret very few people know is there’s an ideal proportion between your vase size and the amount of flowers you should use. I usually work with a 1:4 vase-to-flower ratio, meaning the diameter of the flowers should be approximately four times the diameter of the vase. For example, I wanted the flowers in my arrangement to be about 12 inches across, so I selected a vase that is a little more than three inches in diameter. This ratio makes your arrangement look full. If you use a larger vase with the same volume of flowers, the arrangement can appear skimpy.

Create a support grid

If you’ve ever arranged flowers in water, you know it can be a challenge to keep the stems from moving out of place. One way to solve this problem is to support the stems with a grid of tape along the top of the vase. Florists use floral tape, but I use duct tape cut into ¼-inch strips, spaced about an inch apart. The taped grid on the vase will keep the stems upright. It can also help you map out where to place the different flowers. Instead of a tape grid, I’ve sometimes placed a folded piece of chicken wire in the vase to help support the stems.

Go monochromatic

Another challenge many floral novices face is selecting a color scheme. What colors go together? And how many colors should go in the mix? The best advice I’ve ever gotten about color came from one of my favorite florists: Go monochromatic. I now do almost exclusively monochromatic arrangements, whether for gifts or event centerpieces. This makes shopping for flowers easier, because I only have to look for one color. And, in my opinion, monochromatic arrangements have a more modern and upscale feel. The only other color I introduce in my arrangements is green — in the form of leaves or hydrangeas — because green goes with everything, and it actually accentuates the color of the other flowers.

Even if you’re going with a monochromatic color scheme, select three or four different types of flowers to incorporate various textures. To make my example here, I bought three small bunches of flowers at Trader Joe’s that ranged from $3.99 to $5.99 each — including roses, calla lilies and chrysanthemums. Each of their petals are distinct from the others, so even though they’re the same color, the texture variations provide visual contrast.

Prepare the stems

To create a dome-shaped arrangement, cut the stems of the flowers so that the ones positioned at the edge of the vase are shorter than the ones in the center. Cut the stems at a 45-degree angle, which allows for more surface area on the stems to absorb water. Then remove any leaves on the stems that will be submerged. I know it seems like a shame to pick the leaves off and discard them, but any plant material left in the water will contribute to bacteria growth. (Leaves above the water line are fine.)

Separate flowers by type

Another trick I use when arranging flowers is to not mix the different types of flowers. Like the child at mealtime who won’t let his potatoes touch the peas, I keep each of the different flowers in its own section in the vase. This makes floral arranging so much easier, because it takes the guesswork out of how to combine the arrangement. And again, I find this type of arrangement also looks more modern and high-end.

Fill in gaps with greenery

After you’ve filled the vase with flowers, you might still see a few empty spots here or there. Fill these gaps with greenery, using leaves or succulents from your garden. (Just be sure that only the stems are submerged in water.) Bushy blooms like hydrangeas also make great fillers.

Hide the stems

If your vase is transparent, you will see the stems in the water, and seeing submerged stems is a no-no in professional arrangements. They need to be covered up. One florist friend calls this “hiding the underwear.” Many florists cover the stems by lining the inside of the vase with large leaves. It’s a great look, but the leaves will contribute to bacteria growth. The simplest solution is to wrap a ribbon around the outside of the vase, adhering it in place with double-sided tape. Of course, if your vase is opaque, you don’t need to hide your stems. Still, wrapping a ribbon around the vase can add a nice finishing touch.

What you’ll need:

1 quart takeout container

1 pint plastic deli container

Floral foam

Knife

Flowers

Chopsticks

1. Get a takeout container

The foundation for this arrangement is a 1-quart, or 32-ounce, takeout container. You can purchase takeout containers in different colors at crafts stores like Michaels or Joann, as well as packaging retailers like the Container Store. Stores even sell themed containers for the different holidays. The red fabric-covered takeout container I’m using here is from Pier One.

2. Carve floral foam

Instead of sitting directly in the container, which would leak water, you’ll insert your flowers into floral foam inside a plastic deli container. (I recommend getting a pint of potato salad at the deli and washing out the tub afterwards.) Purchase a brick of floral foam at the crafts store, and carve it with a knife to fit in the deli container. Make sure you select floral foam that is made especially for fresh flowers rather than the kind for artificial flowers.

3. Soak the foam

Immerse the floral foam in water for about a minute, so the foam will absorb the water. Put the wet foam into the plastic deli container, and then place both into the Chinese takeout container. You’re now ready to insert flowers into the foam.

4. Select flowers

I find that the easiest way to choose flowers for this arrangement is to purchase a ready-made bouquet at Trader Joe’s (or any supermarket). This way, you can have an instant assortment of color-coordinated flowers, plus greenery, for less than $10. Cut the flowers’ stems so that they’re all about four inches long, then insert the stems into the wet floral foam.

5. Fill container with flowers

Keep adding flowers until you’ve covered the entire top of the floral foam. Add the greenery that comes with the bouquet, or grab some from your yard, to help fill out any empty spots where the foam is visible. This photo shows the arrangement partially finished, so you can see how the stems look going into the foam.

6. Finish with chopsticks

The finishing element that really makes the arrangement is a pair of chopsticks inserted amid the flowers, right into the floral foam. Go for a decorative pair of chopsticks, not the plain wooden ones you get with takeout. Gorgeous chopsticks are available at Cost Plus World Market as well as specialty stores in Chinatown or Little Tokyo. And when you’re done with the arrangement, treat yourself to a fortune cookie.

The eHow tutorial is here.

Check out the tutorial here.

1) Cut a circle out of a flat of wheatgrass. I flipped the wheatgrass upside down so I could cut through the bottom rather than the grass and used a plate to guide the knife into a circle shape.

2) Place the wheatgrass circle on a platter.

3) Tie a ribbon around the center of the wheatgrass so the blades stay upright.

4) Place flat flowers on the top. The stems of the flowers did not penetrate the roots of the wheatgrass so there is no moisture source. Therefore, I used hearty flowers that do well out of water, like mums and spray roses. They will stay fresh for at least the day of the event.