Collect hybrids from a certain parent A good example of this might be Paph. rothschildiana. Paph. rothschildiana is a very famous slipper species from Borneo. It has long stems that hold 2-4 flowers with nearly horizontal petals that can reach 8" from tip to tip. It has been used extensively in hybridizing and produced fabulous and unusual slippers that carry many of these same traits. Many of it's offspring are awarded. It is fascinating to follow a breeding line to see what traits emerge as dominant.
Collect fragrant orchids. Flower fragrance is complex and often surprising. Many orchids are fragrant and there are many different kinds of fragrance. Some orchids are fragrant at night, some during the day and there are even orchids that change fragrances during the day to attract different pollinators!
Collect miniatures Orchids come in all sizes, but most people don't know that there are many small types. We have some in the greenhouses that are smaller than your little fingernail and have all the complexity of the large flowers. One grower we know displays his miniatures behind a jeweler's magnifying glass so his guests can readily enjoy them in all their minute splendor.