Steps:
Seeing as how the wings on the X-Wing are at an angle you need to start this build about 5-6 blocks in mid-air. Place 5 Red Wool in a row with Quartz Slabs on the top and bottom.

The front end will have a Quartz Block followed by a Quartz Stair.

On the other end place a Quartz Slab on both sides of the last Red Wool Block. Now from each Slab run 5 Quartz Blocks outward.

Underneath this place 2 sets of Stairs facing the vehicle.

Place 2 more Stairs on both sides, connecting them to the once we had just placed.

In the middle of these Stairs place 2 Quartz Blocks.

Connect the front Slabs to the design we just made so that there are no openings underneath.

At the top place 2 Quartz Blocks in the middle with 3 Stairs on each side facing outward.

Place 2 Glass Blocks above the opening, this is your cockpit.

On the sides you will place a Black Wool Block on the front Slab followed by 2 Quartz Blocks and ending with a Red Wool Block.

On the top row you will place Slabs in a set of 4.

You will do this 3 times going higher with each set.

On the end of the wing you will place a Fence Post with Fence Gates facing forward. Repeat this on each side 4 times. The bottom wings will go down not up.

The result is the famous X-Wing.