Decide on a design for your centerpiece. Make it a compilation of twisted balloons, round balloons and maybe even Mylar balloons; Mylar balloons are the foil balloons that come in various shapes and are printed with various pictures. You could also look into making balloon animals or flowers.
For floating balloon centerpieces, make either a collection of various balloons at different heights or a geometrical design. Geometrical designs can be accomplished with balloon molds and ribbon cut into pieces of equal length.
Prepare the balloon weight. Balloon weights can be purchased pre-made but are easy to make yourself. To make a balloon weight, there are several options. You can use a woodblock wrapped in decorative paper and ribbon. Sand filled balloons are a thrifty option. To tie a balloon weight in with the party's theme, use a theme-appropriate object to anchor the balloons. For instance, a stuffed animal could be used at a kid's party, and a vase of flowers could be used at a bridal shower. Be sure to have a weight for each table.
Blow up one balloon of each style. For round balloons that will be used to create a symmetrical centerpiece, the balloons must be the same size. In order to achieve this, you can make a balloon mold from cardboard. Cut a hole to fit the widest part of the model balloon. Blow the other balloons up within the frame to achieve several balloons of equal size. To curl the twisting balloons, curl the balloon around your fingers as it is filled by the helium machine. Make the curl tighter by continuing to twist it into a compact coil.
Cut a ribbon for each balloon, keeping length in mind. You can curl any excess ribbon hanging from the balloons. Tie the ribbon to the balloons and then around the balloon weight. Begin with the balloon that should be in the center. Curl any excess ribbon.