An adjustable composition guide composed of a layer group of vector lines.
A layer group template featuring vector layers making a 4x4 grid iconic circle 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 opacity of all the layers, and enable/disable the circle shadow as you wish! :D
(The circle shadow itself is a raster, but everything else is a vector, so you can adjust this guide if you wish but this should probably be kept as a square canvas for best results)