nstroud

I just purchased a pair of S4i (II) in-ear headphones. It is both my first set of higher-end headphones, as well as true in-ear, canal based phones. Previously I was using the standard iPhone buds, which annoyed me for many reasons, not the least of which was them either feeling like they were going to fall out, or actually falling out, during even basic movement. My question is really this: what should the proper fit of these phones be? Should I be looking for a really tight seal fit (larger bud size), which isolates more noise and gives a more secure feel, but gives slightly more pressure on my ears and isnt as comfortable as the other option. I imagine this will make longer-term continuous listening a little less comfortable. It also feels like the reflective sounds of the bass come through a bit better. Or should I be looking for something a little bit looser (smaller size), which doesnt isolate as much noise, isnt as secure, has less bass presence, but has less pressure and I dont feel them as much in my ear (more comfortable)? I know the classic response is whatever I feel is right but Im looking for expert guidance based on experience with these types of phones. Thanks in advance.