Choose two pieces of 12 by 12, one light, one dark coloured. Cut three 6 by 6 squares from the dark, three 5.5 inch squares from the light.
Score the diagonals of the 6 by 6 squares.
Cut along one diagonal to the centre and cut a tab on the opposite side of this triangle. You will arrive at this shape.
Score a vertical down the middle of the triangle facing you.
Fold the small vertical into a mountain fold, the others into valleys.
You need to make three of these.
Take the three 5.5 inch squares. Cut along a diagonal of two to make 3 large triangles. Cut the fourth large triangle into two smaller ones. Cut the third square along its diagonals to make 4 small triangles. There will be one spare small triangle.
This is one of the small triangles. Score three down the centre to make mountain folds. Leave two small triangles unscored as these will be on the outer edges.
Fold the centres on the large triangles to make valley folds. A small and a large triangle should fit into your previous shapes like this.
Print the folded images with a suitable image. You can decorate these light coloured triangles with a suitable background before stamping. I find it better to apply this background before cutting into the triangles. You can also stamp the triangles before scoring...
Stick the printed images in place and glue the flap.
Print the folded edges down well to firm the creases.
You should make 3 sections - make more to make a more complicated table centre-piece.
Stick the three pieces together.
I used white glue to this point.
Use a die cut machine to make embellishments - I made a flower and tags.
Use double sided tape to fix the tie-ing ribbon.
Glue on the remaining two triangles to cover these ribbon ends. Put together your embellishments.
Punch a hole where required to add the tag and add the flower.
Alternatively these triangles can just be decorated as the interior ones.
P.S. To answer Mary's question below, the card will easily fit in a normal C6 envelope or 5.5 inch square envelope.
P.P.S Another version is to just use DP to mat the triangles...here I have used an image from Ike which I have coloured and then just used as a paper...find the details here