One way to make a big impact in a small space, whether indoors or outside, is to plant flowers in large pots. When you upscale the size of the pot your flowers are in you have the opportunity to create mixed looks of plants or use the pot as a specimen planter where a single plant has a chance to be noticed and shine. The key to using large pots is to not only make it look good, but also keep it easy to manage and move when necessary.
Decide what types of flowering plants you want to grow. Choose a single plant with a mature size large enough to need such a large pot or select multiple plants that need similar soil and sun qualities and will fit together in the pot once they are full grown.
Set your large pot on a short plant stand which has wheels under it before you begin to keep your pot easy to transport from one area of the house to another, or from one end of the patio to the other.
Add a brick or two to the inside of your pot if your pot is lightweight and you think the mature size of your plant(s) might tip it over. Put an upside-down plastic pot inside the pot if your planter is heavier to create empty space inside the large pot.
Fill the bottom of the pot around the bricks or plastic container with an inch or two of gravel. Add potting soil over the gravel to fill the rest of the pot up to the rim of the pot.
Remove the existing pot from your flowering plant and dig a hole in your potting soil as large as the flower's root ball. Set the plant in the hole at the same depth as it was previously growing in. If adding more than one plant, mentally draw an X over the large pot and place one plant in each quadrant with the tallest plant you have going in the center.
Water the plants well to moisten the soil without drenching it or leaving the pot in standing water. Keep the plants well moistened for the first month as they adapt to their new container and then only water as needed.