An adjustable composition guide composed of a layer group of vector lines. You can adjust this to fit a rectangular canvas, or you can adjust this to make the triangles bigger/smaller.
A layer group template featuring vector layers making a golden triangles composition guide, which you can drop onto your canvas and resize, change the opacity of, and otherwise edit and use however you want :3

After downloading, you can find the material in your downloads, and then you can drop it directly into your canvas and then voila! You can adjust the blending mode and opacity however you wish :D
(You can adjust the opacity of the rule of thirds guides, or completely disable them if you wish)
If you want to edit the specific triangles from their current positions aligned to the rule of thirds, but not adjust to fit a different canvas shape:
(so if you want the tips of the triangles closer or further apart than they currently are)
1. go to the "triangles" group
3. delete either one of the layers with "small" in the name
2. select the remaining "small" layer and move it however you wish
-> DO NOT rotate the line (unless its just straight up flipping vertically)
-> its fine if the line extends past the borders of the canvas, but make sure the line you're moving doesn't extend further past the "big" diagonal line within the canvas
-> if you moved the line in any way that it no longer matches the original orientation in the name, feel free to rename the layer to match its new orientation
4. make a duplicate of the small layer that you DID edit (and rename if you wish)
5. use the rectangle lasso tool to select your ENTIRE canvas
6. rotate the new line layer 180 degrees
If you wish to adjust this to a rectangular canvas of any size, rather than a square:
1. select the "rule of thirds" and "rule of thirds phi" groups, and stretch THOSE out to fit your new canvas size if you wish to keep them enabled
2. go to the "triangles" group, select the "big diagonal" line, and switch to the "Correct Line" (default shortcut Y) tool
3. make sure you're on "Move control points" mode, and then drag the two corners of the line to the opposite corners of the new canvas
4. delete BOTH layers with the word "small" in their name and instead make a duplicate of the "big" layer
-> optionally, i recommend you rename the duplicate to "small" + whatever way you want it to be oriented
5. rotate the new small layer by 90 degrees in whichever direction you want, and then move it in whatever direction you need to until you like the shape of the triangle
-> make sure it's 90 degrees specifically!
-> its fine if the line extends past the borders of the canvas, but make sure the line you're moving doesn't extend further past the "big" diagonal line within the canvas
6. make a duplicate of the "small" layer, and rename it to the opposite orientation
7. use the rectangle lasso tool to select your ENTIRE canvas while you're on the new layer
8. rotate the newest "small" layer 180 degrees
9. if the rotated layer isn't aligned with the "big" line, move it in whatever direction is necessary until its lined up properly
Once you've finished making whatever adjustments you want, if its a canvas size you use regularly then i HIGHLY recommend saving your new adjusted layer group by going to "Edit -> Register Material", saving it while these are the only layers on your canvas, and giving it a name to help you remember what canvas size/shape its meant for. Then you can re-import it into future canvases without fussing around adjusting it!