I've learned to put dots at where the seam intersections should be and then match up the dots - when working with triangles and diamond shapes, there are sometimes dog ears sticking out - and that can be confusing to a newbie.

did you look at the quilterscache one? it shows how they are put together in larger triangle units. and pressed very nice and flat too. good luck.

Have you considered trying this?
Practice sewing them together using several of the cut triangles which you have NOT already sewn together and ripped out.

1. Mark your seam allowance on (the wrong side of) both pieces of 3-4 pairs of triangles.
2. Sew a pair together noticing where the intersections of the seam lines meet and making sure they meet on both pieces of the pair.....you'll have to turn it over to check.
3. After you've done this a couple of times, just mark the intersection of the seam lines with a dot, and try sewing 2-3 pair again. Are you still matching the dots on both sides of the pair?
4. If you are matching the sides properly, you can now likely eyeball where this seam allowance intersection is, notice how much point of each triangle hangs over, and can sew the rest of them together without much trouble.

Best luck!

Jan in VA

Don't know if it would help, but this might be a time to try the Elmers School Glue and glue your points in place prior to sewing. Just a thought.

funny, my son chose the same pattern and I started his last fall... luckily for me, he only picked three batik colors so my tumbling blocks were easier to kep together. I took the summer off from quilting but am now ready to pick up the pieces (or strips in my case) and start sewing them together. Yours will be lovely when you get it finished.

you need that 1/4 extending beyond the edge for there to be a turning ease so to speak, otherwise the points won't line up.
if you decide to not go back and fix the others, i'd make them the rows on the bottom and top of the quilt, equal number if possible so it can look intentional and then make the body of the quilt with your points showing.

Neat. Thanks for sharing.

First, you have made good fabric choices. Just keep in mind that each strip should go the way you have on the strips you joined, right leaning diamond, triangle, left leaning diamond, repeat. As Kristakz said, the cutting and seam allowances need to be exact for this to work.

If you are not comfortable doing that RIGHT NOW, do another project and come back to this one. I am not suggesting giving up on it, merely postponing it until you have a few more projects 'under your belt'. Recently, I tried an 'impossible' UFO and found it was NOW really easy for me.

I've made a few tumbling block quilts, and what I see with yours is that you don't have a "light source". The blocks should always consist of three fabrics - light, medium and dark, and those should always be in the same position on each block. The fabrics can be totally different, like a scrappy quilt, but the tones always need to be in the same position. I love your blues and it'll turn out great.

One pt when sewing diamonds together is placing the pieces so that 1/4 inch is off set - you do not line up the corners like you would in sewing a square together - look on line for a tutorial on sewing triangles or diamonds together.