Ribbons are sold separately so you can sew them on yourself, as this allows you to sew the ribbons in an appropriate place for your foot. You can buy ribbons for your ballet shoes anywhere you can buy ballet slippers. Use thick thread or dental floss to sew the ribbons, as this makes them more secure.
Ribbons are sometimes used to tie on flat slippers as well. Some dancers perform in flat satin slippers and use ribbons instead of elastic to mimic the look of the pointe shoe. Flat slippers should fit the foot tightly with no "room to grow."
You can add elastic to help your pointe shoes stay secure. Criss-cross the elastic over the upper part of the instep or sew one elastic looped around the ankle.
Pointe shoes have a stiffened toe box that allows the dancer to dance on the tip of her toes. Only advanced dancers should wear pointe shoes and only with her teacher's consent. Those working in a dance-supply store will help you find the right fit of pointe shoe. Try various brands, as the construction of pointe shoes varies and different brands complement different feet.