I suspect that a quick summary of people's viewpoints on free will itself would help in interpreting at least some answers. In my case, I believe that we don't have "free will" in the naive sense that our intuitions tend to imply (the concept is incoherent). However, I do believe that we fell like we have free will for specific reasons, such that I can identify some situations that would make me feel as though I didn't have it. So, not actually having free will doesn't constrain experience, but feeling like I don't does.

Epistemically:

If I discovered that I was unpredictable even in principle; if randomness played a large role in my thought process, and I sometimes gave different outputs for the same inputs, then I would feel like I did not have free will.

Psychologically:

I have no consistent internal narrative to my actions. On reflection I discover that I could not predict my actions in advance, and merely rationalized them later. I notice that my actions do not tend to fulfill my preferences (this one happens in real life to varying degrees). I notice that I act in ways that go against what I wanted at the time.

Physically:

None. I am tempted to say that losing complete control of my body constitutes a loss of free will, but in reality it seems to closer reflect simply that my will cannot be executed, not that I don't have it (or feel like I have it).

Note: much of this is also heavily tied into my identity. It would be interesting to examine how interlinked the feelings of identity and free will really are.