I used to do parchment craft with my sister when I was younger, but when she left home I no longer had access to it - being the youngest has it's pros and cons! Thankfully the other year I inherited a set of parchment craft tools and some stencils, so I just had to buy myself some paper in order to get back to it!
I really enjoy doing parchment craft, poking the different sized holes through the parchment, and applying pressure in areas to almost "colour" the paper white. It can look so effective, especially when combined with solid colours and simple embellishments.
The most difficult part about using parchment paper in cards is finding the right adhesive, as many show through. I personally found it best to work the adhesive around the design so it was best disguised, for example PVA behind a white area, glue dots behind a highly patterned area, or adding a split pin as part of the overall design. It can also work to leave a larger border around it to stick it down and then frame with another piece of card. I think I need to buy myself some more stencils!