The way I visualize is try to create some images or movies of having it already. I visualize to create the feeling and not to design something I want to manifest in my life. I trust the Universe will find the fastest and most efficient ways to get me there.
Sometimes, when I try to create detailed images... I feel resistance in my body (you know that feeling of your mind/body saying "now thats not going to happen"). Maybe when I have progressed enough, I can create detailed images without having resistance. Because I believe the limits are only in ourselves, the universe has no limits. So when I feel this resistance, I pull back bit by bit to "larger picture" until resistance dies and I am in the flow again.
Ok more practically..... I can see the visions while my eyes are open but when I am doing that nothing in my present awareness is registering... its like I am somewhere else. And yes I would say daydreaming and visualizing are the same. Only you know that one is reality and other is a fantasy. Thats why I think we don't face resistance during daydreaming because we know its not real.
One tip I can give is that the thoughts that we think everyday are soooo important. No matter how much we visualize it won't work if the thoughts are against it. This is more true for people stuck in negative circumstances. I am being more and more aware of my thoughts and it is astonishing what I think... its essentially sabotaging myself. So I am working on aligning my visualizations and my thoughts in the right way.