You could add a plain large border - this one is 8" wide (made with 8½" cut strips). The quilt would work out to about 97" with this size border (the center is 81" square).
This one has two borders. The first one is a small 1¼" border (made from 1+3/4" cut strips) using the same fabric as the dark squares in the alternating blocks. The second "piano key" border is made with leftover fabric from the scrappy blocks - using blocks cut 4"x6½". There are 24 piano keys on each side and the border comes to 6" wide. Corner blocks from the same dark fabric as the first border are made from 6½" squares.This quilt would be about 95" square.
This border finishes the diamonds created by the alternating blocks. I show instructions for these half alternating blocks later in this post.This quilt would finish to 90" square.
This one adds three more borders to the previous quilt. This is the layout I have chosen to make.The first border is a small 1½" border (made with 2" wide strips).
3" blocks made from leftover fabric of the scrappy blocks are the next border. It is made with 3½" squares, and there are 31 squares for each side (124 - 3½" squares in total), plus 4 - 3½" squares of the dark fabric for the corner blocks.
The outer border is another small 1½" border (made with 2" wide strips).
This quilt finishes to about 102".
If you choose to not add a border, the quilt will be about 81" square.Half Alternating Blocks Instructions
These are just quick instructions - I am assuming this is all pretty familiar stuff by now - if something isn't clear and you need more help please email me (joannethreadhead{at}gmail{dot}com).
Here are the cutting measurements for the half blocks (from EQ7).
I decided to strip piece the blocks to make it easier for myself.The strips are about 14" long to make 8 of each block.
The top unit is made with strips that are 3+7/8" wide on either side of a 2+3/4" wide dark strip.The next unit down is made with 2+3/4" strip, 1+5/8" dark strip, 2+3/4" strip, 1+5/8" dark strip and then a 2+3/4" strip.
The third unit is 1+5/8" strip, 1+5/8" dark strip, 5" strip, 1+5/8" dark strip and a 1+5/8" strip.
The fourth unit is 1+5/8" dark strip, 7¼" strip and a 1+5/8" dark strip.
Remember each of these is about 14" long.
Once the strips are pieced, press the seams to the dark fabric and cut them all into 1+5/8" sections.
Piece the blocks together as shown in the picture.
(the colour is different because it is night time)You will need 8 blocks with the dark in the middle and
8 blocks with the light in the middle.
Trim all the blocks to 5"x9½".
You also need 4 Corner Blocks.
I strip pieced them the same way using about 8" lengths for the strips.
The top unit is made of 1+5/8" dark strip and a 3+7/8" strip.The second unit down is a 1+5/8" strip, a 1+5/8" dark strip and a 2+3/4" strip.
The third unit down is the reverse of the second unit and the last unit is the reverse of the top unit.
Cut each unit into 1+7/8" sections and make 4 corner blocks as shown.
Trim the blocks to 5" squares.You will also need 10 light and 10 dark rectangles that are 5"x9½".
These will go in between the half blocks in the border.Follow the picture of the finished quilt for placement of the half blocks and plain rectangles, plus the directions of the corner blocks. 
This is what I have done so far.I was able to find extra fabric (some of the same and some that is similar - you can't tell too much in the photo) to be able to finish off the diamonds and I hope you are able to too, if this is the design you choose.
I have also cut the binding for the quilt using 11 - 2½" strips cut the width of the fabric (my binding tutorial). My binding is the same as the two thin borders (a black print similar to the squares of the alternating blocks).
I apologize if these instructions are hard to follow! It has been a busy week. If there are any problems please email me and I will help.
Next Wednesday I should have the top pieced and a special surprise, so please check back.
Have a great day and thanks for stopping by!!♥