The Photoshop Texturizer filter is a powerful effect tucked away in the gallery and can be used to create amazing canvas effects with any image or text etc. Select the image or layer and go to the gallery command and you will find the required effect in the drop down in between the sumi-e and torn edges.
The key thing for this tool is the displacement maps files. The file format has to be a PSD which is the standard format for this application. You can also make up your own PSD very quick and easily using tools such as the noise effects, blurs as well as shapes and then just saving them as a PSD file. You can use shapes etc to make the designs. You may find it easier to create a set of PSDF files using the same artwork at different scales such as 10% or 50% of the original as the scaling in the effect is limited, likewise, there is no rotation etc features or contrast so you may wish to create a set of designs with different rotations and contrasts as a workaround.
You can use anything as a PSD file, you can fill the image with type such as lorem ipsum or perhaps fill it with blurry dots or noise effects or fill it with sharp lines or diagonal lines or use custom shapes and much more. All kinds of unique designs can be created especially if you are using the latest version with the pattern preview because the key thing is to create a wonderful tile design that is seamless and use that as your source file. You can use non seamless but you will then see sharp edges in your design. It is probably better to create a huge document for the PSD file as well otherwise you will see the repeating pattern.
Use shapes,
Set the map to use. You can then set the scaling for it along with the relief. Change the scaling setting though sadly the range is only 50% to 200% of the original size of the PSD (really not sure why they couldn't extend this range) and set the relief. If you set the relief a low value the result will be very subtle, set it to a high value and you will see the white edging as applied via light (top, etc but sadly not an angle) as well as option to invert. It is a pity that this does not use the foreground color to re-color the edge of the relief.
You can apply the effect to a shape layer and you will see a message - convert the design into a smart object by clicking the convert button. You can always also convert it to a raster layer if you wish or cancel. If the object does not need to be converted, such as a standard layer, you will not see this and to turn it into a smart object, select the convert to smart object in the layer menu. You can now add your effects to the design such as adding multiple PSD textures to the artwork to create a far more complex design than just a single design. You can also add multiple effects and blend between them and use different blending modes and opacities for all of them.
You can use it with color channels and separate color channels. Display the channels panel (window menu) and select the red channel. Apply the gallery effect, perhaps select a different displacement map and scaling and relief as well as light direction. Select the green channel. Apply the effect etc with different scaling, relief and light direction etc. This can be done with any number of combinations of the color channels. You can then combine this in many variations as well as combine other effects such as Gaussian blurs etc to create a slightly more blurry effect in the red to the green etc. You can also apply the effect to the same red channel multiple times and not apply it at all to the green.
You can also use it with selections and you can create a selection using the rectangular marquee or anything from the selection menu etc and once you have the selection, apply the effect to that selection or perhaps the inverse of the selection. The selections can be created in a variety of ways such as using the tools but you can also transform them as well as feather them or expand them or use them as a border and much more and the effect can then be applied to that instead.
You can also use the effect to create unique alpha channels as well by using the panel and the new channel command found in the right side menu. Again, as you have access to an infinite amount of PSDs, all kinds of unique alpha channels etc can be created. Likewise those can also then be manipulated by the feather, expand, border, smooth etc commands.
You can also use the effect with vector shapes, just select any shape design from your custom shapes panel and apply that and set the color etc and then go to the gallery and apply the texture to that shape and as you do that, a panel will pop up and convert it to a smart object or if you wish, rasterize it. You can then add multiple effects to that shape. You can also do the same with type
You can also use it in the pattern preview though it is not much use for seamless textures (be great if the pattern preview allowed for seamless tiles and mirror option) and it will warn you as such but the effect can be applied and the layers etc generated with the texture effects can be added and combined in endless ways
You can use the gallery solely for the effect but by going down to the small duplication button '+' at the bottom of the gallery panel you can also add multiple other gallery effects such as bas relief or emboss or glowing edges etc.
You can use actions to store the information of all the PSD files and settings and playback on other images etc
You can use it with type. You can create a basic set of characters and then apply it to that. You may find that it works even better if you blur the type before you apply it.