First and foremost is a short descriptive title. I like a noun and action verbs. For example "Flamingos Flying." Or "Heron flying with stick". Sometimes an adjective: "Beautiful egret preening." Sometimes a bit poetic (creative), like "Angelic egret preening". And sometimes descriptive and poetic (creative) title with a hyphen: "Sunrise at the beach-The awakening."
If you are doing shows and like poetic titles then use a descriptive title first followed by a hyphen the poetic title you use at shows.
If I have a series on a subject then I number them to avoid repeating titles. And I sometimes number the same subject even if the titles don't exactly match. So Snowy egret I, Snowy egret II and Snowy egret preening III. This helps me avoid repeats.
Titles are as much for the external search the title search here. This is why they must be descriptive or literal, if you will. Don't call a while bird a white angel, because Google may thing it is an angel. (Not sure on this Goggle is getting pretty smart).
Absolutely drop main keywords in the title and the description or just assign your image to the dust bin of the internet. And of course use those words in the tag section.
It is important to think of a keyword as a word that matches what the searcher is looking for as well as a clue for the internet search engines. Keywords are not just something in the tag section, but they should be in there too, mostly for the site search.
And always do all the tagging and descriptions on upload. Remember that newness matters on this site and on external search engines. The clock starts ticking on upload. If you don't have time to do it then don't upload until you do.
Good luck and a rising tide floats all boats.