Stenciling -- Who knew it was this hard?

I tried my hand at stenciling. First try was fairly sad:

Mike suggested that painting on bare cardboard might have made the paint run, so maybe putting down a coat of white first would help. It really didn't:

So I finally decided to wander through the Internet to learn how to do it. Apparently I was doing at least two things wrong. First, the paint brush should be dry. Dab it in the paint and then brush most of it off. Then the paint should be applied by 'dabbling,' not 'brushing.' The results this time were marginally better:

However, it would appear that I need lots more practice before attempting it on the real pieces for the dollhouse. Or decide that un-stenciled windows and doors still look fine.