Double T combines two common blocks that we've visited several times before, and creates a wonderful secondary pattern when combined with each other.
The two familiar blocks we'll be using are HSTs /Half Square Triangles (for instructions see BOW #1) and Flying Geese (for instructions see BOW #6). The Flying Geese units have a "twist" to them that you'll need to watch for--not difficult, you just have to make sure you get color placement right.
For a 12" finished Double T block you'll need:
(1) 4-1/2" square Background color
(2) 4-1/2" HSTs that are half Background and half Color 1
(2) 4-1/2" HTTs that are half Background and half Color 2
(4) 2-1/2" x 4-1/2" Flying geese arranged with Color 1 on the left and Color 2 on the right
(4) 2-1/2" x 4-1/2" Flying Geese arranged with Color 2 of the left and Color 1 on the right
Arrange the HSTs and Flying Geese as shown, with the Background square in the center; be careful about the placement of the Flying Geese so the pattern is correct.
When you put four of these blocks together you get a secondary pattern, which is the same pattern, really:
This would be a wonderful quilt in red and green and white (or cream) for Christmas. It might even be kind of interesting as just a two-color quilt, like blue and white, or red and white. (And then you wouldn't have to worry about the color placement on the Flying Geese!)