Feeling a little lost

I'm trying to decide on my experimental design. After meeting w/ my PI I feel a little bit lost. I present an idea of what I would like to do, and then hear about how that seems a bit difficult and maybe we shouldn't try that. So I modify it or come up w/ a different approach and then I hear the same thing. Sometimes the critique is really good and helps to point out a flaw. Other times I feel like because it is different she doesn't want to try that....

I guess I need to work on my communication skills, and work on pushing forward ideas I believe in. In my old lab, my PI and I would discuss ideas and then if I said I want to do X and then X she would say great! lets do it! (of course sometimes she would have suggestions to change things and we would talk out, do x first, then y because of... etc) but I got to do experiments and she was willing to try different things. Here, I'm told, "lets hear about other task designs" but when I suggest one I hear "Lets, not do it that way, lets modify it to be like how we do our other tasks"

Which in this case won't work that way. I feel pressure to decide and get this process started, but I also feel like everything I come up with isn't what she wants.