Firstly, the items that you would need:
A note on the papers: I chose a striped paper for the central rectangle and the same pink/red colour for my backing rectangle. Choose a solid colour that is part of the patterned piece of paper and find a piece of paper that colour for the 'backing' rectangle. Usually a darker, rather than a lighter colour, works best.
1. I like simple designs, so my card is made up of two rectangles and an embellishment. If you are making the card with young children, you may wish to pre-cut the rectangles and get them to do the gluing. Don't fuss too much if their rectangles are off centre, it is their own special design. To make the 'backing' rectangle, measure a rectangle 7cm x 8 cm on the solid colour paper (with the ruler and pencil) and cut it out. Glue it just above centre on the front of the card.
4. If you like, add a sentiment underneath the rectangles. I used a gold sticker, however, you can use 'rub on' sentiments. For children, I type some sentiments on the computer and print them out on coloured paper. The children cut a sentiment out and glue it underneath the rectangles. You could simply, write a sentiment. A finished card!
6. If you want to add a special touch to your card, you could add a liner. Fold a piece of paper that is the same size as your whole card, in half. Trim the liner to fit just inside your card (if necessary) and glue it down the centre of your card. You may wish to glue down one side of the liner, not the whole liner, otherwise the liner tends to bubble when the card is folded.
This same card making principle could be used to make birthday and thank you cards. Changing the colour scheme to more 'earthy' tones would make the card more masculine.