The only site I have been to - and that was a few years ago - was Glasshouse Mountains north of Caboolture. I drove up one of the forestry tracks and found a clearing - but the trees were getting a bit tall. Worth a daytime reconnoiture.
Another place I have meant to go which would be good is Mount Mee State forest park. They have a grassy picnic area with lots of room and trees far enough away. You get there by turning off at Kallangur, through Petrie and on to Dayboro. Then hang a right up to Ocean View and Mt Mee .
If anyone knows anywhere else, please also let me know. I have been a bit scared of going out to a dark site at night - by self or with wife. There are a lot of wierdo's out there, and the thought of having an encounter with maybe a busted scope or worse - has put me off a bit.