sigh, photography, even harder than planted tanks...
FWIW, there's a guide over in the "Member's Aquarium and Fish Pictures" called "Taking Great Fish Photos (How To)" and there are other great posts to be found from over the years is you do searches.
Note that the guys who take photos for the aquarium magazines, when you see them in real life, are like those fashion photographers with thousands of dollars of equipment.. big Nikons with big lenses, remote flash equipment, the whole nine yards.. so don't get down on yourself. Practice and effort can produce good results, we've seen here.
~~waterdrop~~