[Darth Wader (Wade)]

I've read on this forum and many other places of people viewing moon transits on Jupiter and Saturn, Jupiter's great red spot as well as seeing the polar ice cap and dark features on Mars. I have a collapsible 8" dob and even under optimum conditions I have not managed to see any of these things. The planets are bright, maybe a little too much, but no detail is visible (save for the two cloud bands on Jupiter). Mars has been especially disappointing as all I can see is an orange disc at times of (what I thought was) good seeing. I have read of people with the same aperture scopes seeing them - what am I doing wrong? Could it be because I don't have a light shroud? Do I need filters/higher mag/proper dark skies? Am I better off with more aperture (I can be easily persuaded to upgrade to a 12" dob - in fact, I'm looking for an excuse)?

Thanks in advance

Cheers
Wade