How I Make My Own Cards
I have made my own cards for several card games — Magic:The Gathering, Fluxx, Munchkin and Super Munchkin — so I've tried a few methods.
The one with the best results I found so far is to print your card onto a large self-adhesive label. Then turn the label face-down onto a clean table top and peel off the backing. The printing card should show through the label so position the blank card face down on top of the sticky-side-up label so that edges match up. Finally, with a pair of sharp paper scissors, trim the label down to the cards edges.
If you want to give the finished card a bit of protection, then coat it with matt varnish spray from a model shop.