The most important thing for CFD's (in my opinion) is to always have your stops in place and ready to go..
Have a plan ready. Work out how much you can afford to lose and what your margin is..
With CFD's there is always the potential to lose more then your initial deposit on a stock, so have your stops in place and ready to go once you place the trade... Plus 500 is pretty good that way from memory. You can adjust the stop at any time.
When I place a trade I always set a limit to my loss of about 10%, that way any surprises will cover me if the stock dips quickly if I go long, or if it rises quickly if I go short..
The beauty of CFD's is the exposure, if you get your loss strategy right you can certainly make some good money and expose yourself to a holding a much larger position in a stock then you otherwise normally would.
Get your trading strategy sorted and the rest will sort itself out..