I recently finished weaving enough triangles on my pin loom to create a hat, which I love. My triangular pin loom has the pins closer together than my square or heart, so fingering/sock yarn is perfect. I love the way the sock yarn weaves up on this loom, although sometimes with yarns that have longer colour changes, the triangles are just a single colour. It's fun to see how each yarn behaves on the loom.
I finish all my pin loom weaving pieces by crocheting a slip stitch border around the edge. I like this better than just leaving the loops as they are when they come off the loom--it adds a nice frame and it gives a sturdier edge for connecting pieces. In this case, I decided to add another crochet border with dark blue laceweight yarn, which made the colours pop.
To start, I put four triangles together to form a square, which became the crown of the hat.
Then I added triangles along each edge, point side down. The next round was triangles in the corner spaces, points towards the corners. Then two more rounds like that, before a couple rounds of crochet at the brim.
