It's easy to use that 1.8" TFT with the right pin numbers and the Adafruit libraries for the display. I just got it going yesterday. Look at my post on Google+https://plus.google.com/u/0/116599331662269985445/posts/XUoZT3dCG27
And the comments.
Here's the key. Look in the first lines of the graphicstest sketch from Adafruit. You should change them to look like this:
// You can use any (4 or) 5 pins
#define sclk 15
#define mosi 16
#define cs 7
#define dc 0
#define rst 1 // you can also connect this to the Arduino reset
You'll also have to rotate the display to landscape. Comments on my post show how, or you can read the tutorial pdf from Adafruit.