With feral kitties, it is tough....
i think those that display plenty of animosity might have experienced human abuse.. thus, no matter what you do, they just would not come up to you...
i feed 7 kitties outside my backyard, and along the way, i see different kitties come and go as well... i think they jump from backyard to backyard... or only God knows how some people react to them.. i just hope and pray that people would NOT be cruel to them or hit them...
Last September, i "fought" with a neighbor's teenage daughter when she kept throwing a basketball at Browny (one of the feral kitties i was feeding at that time) when she jumped onto one of their tall trees.
i was really furious, and when i went over to give her a lecture, she claimed that Browny was scaring her pet mice. That was bogus, as i did not see any mice. i told her to be kind to animals, etc, etc. i really went over to give her a piece of my mind!
Her mom and uncle just stayed quietly in the kitchen while i rattled on and on. i guess they were shocked and surprised, as i am normally pretty quiet and subdued in this neighborhood. That is one thing that can really tick me off -- people being cruel to animals.
Back to your case, i would just put out fresh water and yummy foods.. it is just one of the ways to tell them "i care for you."
What about throwing them some small furry toys? Also, setting a bed under a shelter might be workable. i did that, and i see Cindy and Adonis sleeping there almost everyday. Also, i spot my Gabriela sleeping in her favorite spot in the backyard as well.
i change the sheets/soft towels that they sleep on once a week, and straighten them out whenever needed... these kitties can be playful you know?
Thanks for being an angel and for feeding them!