I'll be honest -- I'm not big on "Skills" and "Tips" for relationships. I firmly believe that most of us have the "skills" we need to communicate effectively; most of us do it just fine in most of our less significant relationships. It only goes wrong in our intimate relationships because the stakes for getting it wrong are so much higher. We start protecting ourselves, or our partners, or ourselves via our partners, and then the messages we send get muddier and muddier.
So when I encounter smart, informed, and sensitive clients who have heard about "I Statements" and try to use them, I argue against it. So often an "I Statement" is just a veiled accusation. You cannot put an "I feel that" in front of any other statement and transform an accusation into something open and vulnerable. "I feel that you..." or "I feel that s/he..." is a recipe for a defensive response, robbing you of being really heard and understood. If the words, "I feel" are not followed by an actual feeling word (i.e., happy, sad, angry, shame, surprised), it's worth taking a pause to consider what you're actually doing there. That being said, there is a kernel of something true and important in the idea of an "I Statement" that, in my opinion, keeps this over-simplification alive in the relationship counseling zeitgeist.
What I will often do to get at the heart of this truth is to point out when my clients are telling their partner about their partner, instead of about themselves. I will then challenge them to try to say what they just said speaking ONLY about themselves, speaking only of their own experience. "How would you put that if you were to talk only about you, and not tell your partner anything about them?" You can, of course, point out something you saw or heard, from the point of view of your experience, so you will inevitably mention something they did. But the intention is to not tell your partner about them, to only tell them about you.
What does this do? Yes, it tends to reduce the sense of accusation, and therefore the possibility of a defensive response. But it also does this more important thing; it forces you to really think about what it's like for you, this moment of pain or distress you are trying to communicate, and it forces you to try to let your partner INTO THAT. What it's like for you.
Isn't this the very essence of empathy? The ability to put one's self in the shoes of another, to place yourself into the experience of someone else? When I think about what something is really like for ME, I can touch the depth of feeling at the heart of that experience. And when I share that with my partner, I engender a sense of empathy in him/her. And now we are connecting.
So next time you want to try on an "I Statement," think less about how you can make it start with "I," and think more about how you would share this experience if you were to avoid telling your partner anything about them, and only speak about yourself. Imagine putting a go-pro with microphone inside your head, and showing this movie to your partner. The camera, the mic... they don't have access to your partner's thoughts, intentions, or feelings, so the movie can't speak to that. You can, however, speak in depth about your own perceptions, intentions, and feelings. You can speak to what it is like for YOU.