All of my drapes are lined which gives them some weight, and I do use fabric with a bit of weight too. Both of these things help the drapes hold the pleats, but the same idea works well for unlined also.
The placement and number of rings is a major factor. Too many or too little and they won't hang properly. I've made all the drapes out of 56" wide fabric and using 7 rings is perfect for this width.
The two end clips are placed in from the side of the panel so the side returns back to the wall and window and there are no gaps. The rest of the panel is divided so that you place the remaining 5 clips evenly across the panel. Then I pull the space between the clips forward to form the pleats.
I don't puddle any of my drapes, I just hem them to barely skim the floor.
Next is what I call finger pleating. I follow the fold of the panel that is pulled forward on the rod down to the hem and use two fingers to gently fold them into pleats. This doesn't create any sharp edges, it just allows the fabric to naturally follow the line from the top to the bottom. Just take the index and middle finger and place the fold between them and run up and down the fabric.
That's it. They still have a casual feel, but the pleats are all in line with casual folds that hang in a nice flow up and down the window.
Hope that answers the questions. This is just my own method. Let me know your secrets.