When factory sourcing, you need a sample. You need something tangible to show booth reps; so they can see what you want, and not just hear about what your needs. If you cannot bring an actual sample of your idea or item, then make sure to bring along a detailed sketch. A detailed illustration showing stitches, seams, and all details works well in lieu of a physical sample. If you do not have either of those, then wear something quite similar, or mock up a sample by fashioning it out of other items. A sample is important, as at production sourcing shows, the representatives in the booths are from the many different countries and English may not be their first language. Therefore they may not completely understand your idea, without visual accompaniments. A description alone does not provide enough specifications to a rep so that they can give you accurate information on whether they can or cannot produce the item, how much the item will cost and how long it will take to make your item.
Alternately, if you have an existing line and website, you can pull up your website and show the booth reps your product pieces online. However, do understand that photos alone do not show the particular workmanship and quality you are looking for. So do have a sample and/or sketch made before you source or create them yourself.