Depending on the type of cattleya you are growing, I would simply suggest that you keep doing what ever it is that you are currently doing. If you have plants that are already becoming specimens, then you are on the right track. As far as cattleya orchid care, here are some basics:
2000 - 3300 footcandles
Out of all of the orchids commercially grown for sale, only Vandas surpass the Cattleya in light requirements to bloom abundantly. As a general rule, give plenty of bright light!
70 - 90 degrees F. daytime, 60 - 65 degrees F. night.
40 - 65 % relative humidity is ideal
While Cattleyas adapt well to less than ideal conditions and therefore make good "beginner" orchids, their high light requirements are sometimes difficult to achieve in the home. Be sure to place them where they will receive abundant light with direct sun striking them only very early in the morning. Allow them to dry slightly between waterings.