The hardest thing to do is to transport your irises without breaking them or knocking off the buds. There are several ways to do that. Our biggest show person brings his irises in his van with "vases" made from PVC pipes hooked together so that they have water as well. I am not that inventive so I use an old drywall bucket and roll up newspaper into tubes until the bucket is almost filled then I insert the iris stems into the openings in the rolls of newspaper. I have also used cut up pool noodles that have large holes and also styrofoam pieces that are round (my son has them from HVAC packing) and add water to the bottom of the bucket. This keeps the irises from knocking into each other and also keeps them hydrated. You must pick stalks that still have the top bloom or you will not win. Candelabra shaped is best with the flowers not touching the stems or each other.
Hope this helps. I won Queen of Show on my first try at it but it is harder than one would think . It all depends on what you have blooming at the time that fits the bill. You can cut one that you expect to bloom and bring it inside and put it in a warm shower room. Some people refrigerate ones that they do not want to bloom too soon but my fridge is not that large.