Having greeting or thank you cards personalised adds a nice touch to the timeless classic but transparent cards are even nicer and you can make them at home!
A transparent greeting card is made by printing a design onto a OHP transparency (see below for suppliers) using a normal inkjet printer. The transparency is then laminated creating a custom transparent greeting card. You can see the step by step process of making transparent greeting cards over here (same process).
Now the key to a good greeting card design without having good design skills is to find a nice background. You can use free image sites such as freeimages.com or Unsplash. Then simply overlay a message in a nice script typeface/font. You can use a software like Microsofr Publisher or Inkscape which is free to lay out the card.
OHP transparencies are not as common as they used to be but large stationary shops such as Waltons sell them. Lamination pouches can be purchased at many places.