How can I prevent my balloons from tangling during transport?
Are you talking about transporting balloon bouquets or balloons on a string that you want to hand out as gifts, for example during a parade?
If it's the latter, I've written about how to prevent the balloons from tangling here.
If you are talking about transporting balloon bouquets, i.e. several balloons tied to a balloon weight, there's a special clip called the "Balloon Tamer."
The trick is to temporarily shorten the length of ribbon between the weight and the balloon. I've uploaded an image of the clip attached to a balloon bouquet with shortened ribbons. The video below shows how to use it.
I am not sure though if this "Balloon Tamer" is still being sold. You can contact the producers via their website.