You can't be thinking about this so much. One of the best parts of a passonate kiss is that you arnt thinking, you will never get there or ever enjoy it if you are thinking. Rule 1) Stop thinking. But if it helps you to stop thinking eventually, here is what usually marks a passonate kiss for me. (I'll try and keep in the realms of simple making out that doesn't go too far).
Open mouths
Hands in hair/ back of neck/ hips
You are generaly pressed up close (as much body contacting at one time as possible)
Changing positions. Variety is good. Try standing, against a wall, on bed, her on top, you on top, sitting, side by side laying. Just keep moving where your body takes you.
Sucking on upper/ lower lips
Some tongue fun
Kissing other areas (i.e. neck, ear lobe, peck on the nose, cheek, across collar bone)
If you are by the ear it's sexy to hear some heavy breathing (at least I like to hear her)
And its always has good to aknowlage the good time you are having in a flirty way. Her response can tell you how far you are allowed to go
And you have to be willing to let your hands roam a bit, women usualy wont initate things, they are expecting you to go there first, even if you are rejected it doesnt mean she wants to stop everything you just need to back off for the time being and try again another time, always be respectful of where she wants you hands or tongue or lips at any given time.
Always remember not to harp on the same move for too long, you want to explore a variety of things, and places, it keeps it interesting and it can keep you up for hours.
When you get that far come back and we will help you get that bra off.