Select a base for your arrangement, such as a candlestick or floral urn. The cone shape should be approximately twice the height of the container. You can also purchase preformed cone topiaries at craft stores to elevate your cone design.
Affix the floral foam cone to the base container using hot glue or floral putty. If you are using fresh flowers, choose a cone that is specific for fresh arrangements and soak the form in water before you fasten it to the container.
Cover the base of topiary shapes and open areas between the cone and container for non-topiaries with moss. Use floral pins to secure the moss in place.
Insert the largest flower blossoms into the foam. You can create an orderly arrangement by placing the blossoms symmetrically around the foam or a free-flowing design by scattering the flowers randomly. If any of the blossoms have weak stems, wire a floral pick to the stem and cover the wire with green floral tape before you insert it into the cone. Position the largest blossoms closer to the bottom to keep the scale appropriate. Trim the stems as necessary with wire cutters or floral shears.
Place the smaller flowers around the large blossoms, filling out the arrangement. You can hot-glue silk and dried flowers to the cone shape rather than inserting the stems into the foam as well.
Fill open spaces with greenery, berries or tiny filler flowers to complete the arrangement.