There are a few suppliments that you can use that are somewhat worthwhile. Zoe and Selcon as mentioned in that article are decent and not complete snake oil. Be that as it may, I think an aquarist's primary concern should be variety. I try to give them something different everyday. Various different types of frozen marine mix (some veggie oriented, some meat oriented), mysis, spirulina brine, krill, nori, a few different types of flake food (I like Omega 1 branded types since they tend to have good quality), Hikari pellets, roe (fish eggs from asian market), and a frozen mix done locally by a member of our local club.
I know people who swear by suppliments, especially for coloration, I guess I just never got into them.