Summarize this article:

If your design involves adhering objects to your shoes, arrange the pieces on your shoe or on a flat surface to determine the layout. You can also mark the placement onto the shoe with a small dot, using a permanent marker. During this stage, verify that you have enough materials to complete your design.  For instance, if you’re making a rhinestone starburst shape, lay out the individual gems in the correct orientation and make sure you have enough to cover both shoes. If you get stumped, browse online for shoe design inspiration and make a list of fun, stylish, or personalized decorations that you might want to add to your shoes. Wipe the dirt and grime off of worn shoes using a damp cloth before you start decorating them. You can find pom-pom trim or tassel trim in the ribbon aisle of most craft stores. Cut off a strand and secure the end to a narrow sandal strap using a dot of hot glue. Wrap it around the strap and continue onto other straps, securing with another dot of hot glue every few inches.  Make sure you don’t wrap the trim around the buckle or closure. Undo the shoe closures before you start wrapping to ensure that you’ll be able to put the shoes on later. You can also use individual pom-poms and tassels. Just tie the loose ends around the sandal straps, or cut a short length of yarn or ribbon to tie them on with. Add a dot of hot glue to keep them in place. Cut out your fabric decorations. This might be a length of ribbon that you tie into a decorative bow, a felt shape such as a star or heart, or a pre-made fabric flower. Apply hot glue directly onto the shoe and press the decoration firmly into place until the glue hardens. Place your hand on the inside of the shoe behind the decoration for support as you press it on.  Try using a row of fabric flowers to completely cover a flip-flop strap. Felt cutouts details can look nice on the toes of ballet flats. Have fun creating whimsical designs with felt, like a cat on one shoe and a mouse on the other. When you’re deciding where to attach 3-dimensional decorations, choose a flat spot on the top of the shoe that won’t get crushed when worn. While you can purchase new charms, this can also be a fun way to upcycle old accessories! Use jewelry pliers to open the jump ring or split ring. Wrap it around a narrow sandal strap and pinch it closed with the pliers.

Summary:
Create a layout for your design using the embellishments. Wrap pom-poms and tassels around the straps of your sandals. Hot glue ribbon bows, fabric flowers, or felt cutouts onto your shoes. Clip jewelry charms onto strappy sandals.