Beautiful quilt. My first thought was to quilt following the line of the diamond shapes ie diagonals. One line through centre of each block.

Very very pretty!

I would love to see this quilted with orange thread in wavy lines. Wavy lines are a modern type of quilting design and are very easy, especially if you have a walking foot. You simply start at one edge of the quilt and move the fabric gradually from side to side as you sew. Because the lines are wavy, they are not expected to exactly mimic each other (unlike straight lines, where it is easy to see a deviation). I will see if I can find a photo or two of what I am describing..... Ahhh, here's one!
http://www.canoeridgecreations.com/2...1_archive.html

Beautiful quilt! I think stitch in the ditch is perfect for your quilt, and gray is a good color for the thread if you are a bit unsure about your stitching. Like others have said, check your batting to see how far apart is okay. I use Warm and Natural and you can quilt as far apart as ten inches. If it is hard to get the quilt through your machine, the fewer stitches you have to have, the better! I think I would stitch around each block and then do one diagonal through the center. I just love your quilt. You are doing really really well!!

Dina

Ive done like tess with crosshatch. works fine!! Your doing great your 4th quilt! Wow!!

This does not look like a beginner's quilt. Great job! Have you considered using grey thread to quilt it?

I am so impressed, you have done some great work, very creative.

Very nice! Can you give us a link to the pattern? Sorry.. no help/advice with the quilting but you are doing great!

Beautiful on all counts. What pattern ? Square within a Square? I think orange thread will take away from the beauty of our quilt. Grey is a good idea.

superb everything: pattern, colors, piecing! many excellent suggestions given already. I am not going to add to this. I can't wait to see it finished.