Spectacular Symmetry Photoshop Art is super easy to do with this feature. The feature is available via the edit menu in the fill command and pattern content and script 'symmetry'
The start point is a source tile and this can be anything such as an image, text, shapes, chunks of an image and much more. A good start point is a vector shape as it can be any size. You may wish to have a tile of 1000 x 1000 or perhaps a tile of 100 x 100, well, the vector shape is the ideal resource. You can fill the vector shape with gradients as well as tiles and also solid colors. Select say the custom shape tool or ellipse tool and set the option to a 'shape layer' and then apply it. Avoid going over the edges unless you want a sharp line in your design.
You can define it now but personally think it works better if the background is removed so you have transparency, another reason for going for the vector shape layer approach. Select the entire image or close to the actual design, I prefer the latter so use the rectangular marquee tool to select the object. You can also add a layer style if you want to add some depth to the image, such as a drop shadow via the layer menu and layer styles and drop shadow. Now, after all that, define via the edit menu
You have the preset stored away in your preset library. Go and make another document, perhaps three or four times the size of the document and generate a new layer via the new layer command. Go to the edit menu and fill. Choose pattern as the contents and select the preset you just made and then set the script check box to ON and then set to symmetry fill and click OK. Another panel will then appear (it is a pity that they went for a two panel approach)
The next panel does not have the preset listed so if you have chosen the wrong one, you will have to just cancel and then re-try. Set the scale, set the width / height as well as randomization for the colors etc. Set the type to '7 Dilative rotation'
You can vary the scale. The preview is not much of a help as the preview may show the design is too big or too small and you may go over the edge of the document (not that is an issue if you only want to use it as a single layer). Annoyingly the scale only goes to 1.25, I am really surprised they have never increased that maximum value. You can also add effects to the image such as stylize oil paint
You can change the result very quickly by modifying the translation along width and height and there are a number of different combinations that can result in a radically different image (it is a pity that there is no randomizer feature here)
The design can be applied to a layer and as a layer the design can be duplicated and fill the entire screen with the work as well as re-sized and rotated.
You can develop millions of different designs even from a slight variant of a basic circle such as making the circle thinner and distorting it slightly using the direct selection tool and then perhaps having multiples of that shape and then define that as a tile via the edit menu. Again, delete the background otherwise you will have the white background included.
The preview rarely matches the end result or certainly the part of the image you see in the preview. I think the preview would be brilliant if you could zoom in and zoom out or pan across it but the result just shows a fragment of the end result, makes it hard to know what you will get. You could change the settings over and over but without the proper preview, it is a lot of trial and error and the slightest change of the height / width can result in quite a radical change
You don't need to use a colorful gradient fill, it could as easily be a shape filled with type used as a source. The shape can be modified by using the direct selection tool and layer styles such as color overlays can be added. The type can be as is or blurred, etc
Vary the width and height and scale in the effect to make many different type filled designs.
You can also use opacity and blending modes when you add and apply your fill. You can use difference etc to great effect as well as opacity to devise a more painted design. You can also combine with filters such as oil paint
You can also combine multiple applies of the fill command with the different blending modes and then combine the end result with an adjustment such as a vibrance.
You can apply the fill and then go to the edit menu and fade the fill. You can change the opacity and you can also change blending mode for the fade
You can also record the steps for this in an action. Goto the window menu and actions and then start the recording (the little +) and then capture the steps for creating a design. You can then repeat this action at a later time or just use the action to quickly re-apply the effect
You can then re-apply the action over and over, perhaps use on different layers,combine with other effects such as blurs and much more. You can also apply the effect to a set of folders if you wish via the file menu and automate and batch and process the effect on a bunch of different files.