margecam52

Since you have already cut your pieces out...here is what I would do..
First...to make it easier...let's number the pieces by color:
1= bronze diamonds (4 pieces)
2= black diamond (1 piece)
3= Gold arrows (2 pieces)
4= black half diamonds (2 pieces)
5= black half arrows (4 pieces)

We will do them in strips.

First you want to stabilize the pieces. You can starch them...but make really sure to use a heavy starch (spray starch)...spray...press (don't iron back and forth...press down, lift up. When the starch is dry...repeat.

Now, draw your 1/4" seam lines on the back side of each piece...use a chalk pencil, crayon, whatever...just make sure it's exactly 1/4"...let the lines you draw cross over one another at the tips...this is very important...where those lines intersect is where you stop stitching...only stitch up to that intersection and stop...you can back stitch one or two stitches to make sure the stitches won't come out later.

Seperate into three sections...
Section 1... a black half diamond from the left in your picture + a bronze diamond + a gold arrow.

Section 2 ... a black half arrow from the bottom left in your picture + a bronze diamond, the black diamond + a bronze diamond, and last a black half arrow (top right in your picture).

Section 3... gold arrow + bronze diamond + black half diamond.

The other half arrows will be added last.

Take the pieces to section 1 and line up the intersections exactly... the drawn lines are your stitching lines...except remember to stop at the intersections.
Start by sewing a black half diamond to the bronze diamond...now sew the gold arrow to the other side of the bronze diamond. That's section 1...set it aside for now.

Take the pieces to section 2 and sew the black half arrow to one side of the bronze diamond. Sew the black diamond to the other side of the bronze diamond. Sew a bronze diamond to the other side of the black diamond. Last...sew a black half arrow to the other side of the bronze diamond.
Set Section 2 aside.

Take the pieces for section 3 and sew the gold arrow to a bronze diamond, now sew a black half diamond to the other side of the bronze diamond. Set aside section 3.

Press all seams as you go ...I usually press to the dark...it's a matter of preferrence...for diamonds, some like to press the seams open...I don't.

Carefully match the seams of section 1 to section 2...Pin if you have to & stitch...don't stop at the inside intersections, except to make sure they match...this will be a single line of stitching to join the to pieces. I leave the outer 1/4" seam unstitched for joining the last pieces...it's just easier for me.

Press.

Now join section 3 to the bottom side of section 1-2 combo. Again, match the seams.

Press.

Now you can add the last black half arrows. This will be almost a y seam. I have learned (Thanks to Alex Anderson) that if I don't stitch inside that 1/4" seam allowance...just right up to it...Y seams are a breeze.
Stitch the short side of the half arrow to the diamond...stich just up to the intersection.
Press
Now stitch the last long seam & press. This should give you a nice border piece.

The things to remember, that you must have are:
1. perfectly cut pieces
2. perfectly marked 1/4" seam lines that intersect at every point/turn.
3. Starch ( I have also used a lightweight fusible interfacing to add body to the pieces cut on bias...but starch is less costly.
4. Don't stitch past the intersection marks.
5. Don't worry if it looks like the diamonds don't match up...if your stitching ends at the intersection on both sides of the unit...you are good...points of diamonds may stick out...you can trim them when you are done.

Hints for next time...before you cut. Learn to do diamonds via strip piecing...so much easier...lol

Mark the seam lines before you cut out the pieces...yes, time consuming...but once you have done several, you can just find the intersection and put a dot there.

Starch your fabrics a lot.

I find that when cutting diamonds...if I cut them on the bias...my edges are then on the straight of grain...stitching is much easier, and I am less likely to stretch the edges..so no wonky seams.

I hope this is clear enough for you.