Initially after reading the title, I thought you were looking to make textures, but it appears you were looking for advice in a different area... But just in case you are not aware of it, here are three good options for making your own textures...
• Filter Forge- https://www.filterforge.com/filters/
Filter Forge is a node based texture generating program that will allow you to render out images of over 11627 available user made filters, modify existing ones, or make your own (depending on the version)... The site also has many lower resolution (516 x 516 pixel) seamless images used as examples of what the individual filter look like that could probably be used in many projects if you are not interested in the actual product.
Filter Forge comes in four versions...
-Basic: Around $149 USD, This version will render up to 3000 x 3000 pixel images of any of the user made filter collection of filters up to the current version you purchase (for example the current version is 5, but when 6 comes out and people start making filters in 6, you will be limited to ones for version 6, unless you upgrade... This applies to all versions except the subscription version). Basic does not render bump, normal or occlusion maps and you can not alter or make your your own filters with it.
-Standard: Around $249 USD, this version too renders up 3000 x 3000 pixel images of the user library collection, but you can make your own or alter other user's available filters from the library. It does not do bump, normal or occlusion maps. Probably the best bargain if you are not in need of the Pro features.
-Professional: Around $399 USD, this version will render images up to 65,000 x 65,000 pixels (I have no idea how they tested that, but most computers would just melt doing that). You can render bump, normal, ambient occlusion, metallic, and other specialty maps, make your own filters, or alter existing ones.
Professional Subscription: $29 USD quarterly. Same features as above, but in subscription format, not affected by version changes if you stay subscribed.
Note that with the above prices I have said "Around $____ USD", this is because if you are patient, you can probably catch a really great sale... Often I have purchased upgrades for 70%-80% off... Also from what I understand all versions (except subscription) have the ability to purchase a permanent license key for more money and that option also will reflect any sales percentage offered.
There is a free 30 trial demo available, it is fully functional, including the ability to render out any filters you create or download.
Lastly, Filter Forge has a unique gimmick... Users who download very popular filters can earn points to apply to discounts, upgrades, or even a free upgrade... BUT... This is fairly hard because it is subject to usage statistics, not downloads and some users may not wish to share their usage stats.... But in the event someone is great at filter making, it's nice have the option, plus it encourages new filter additions to the library.
Filter Forge is available for Macintosh and Windows.
•Genetica- http://spiralgraphics.biz/index.htm
A node based texture generator similar to Filter Forge but with many unique differences (depending on the version), such as drawing tools, visual styles (similar to Photoshop's "styles") and the ability to create animations. It is available in three versions. I do not own Genetica and the website is pretty flat in what their features mean, so in this instance I can not provide as much info other than what I see and understand.
-Basic: $149 USD. Renders up to 3000 x 3000 pixel images of filters... It appears though, that you can make and alter filters with this version... But I can not confirm that. You can render bump, specular, luminance and "other" effects maps. Has drawing tools and visual styles.
Pro: $399 USD. Renders up to 6000 x 6000 pixel images. All of the above features, but also gives you the ability to import UV mapped models for texture work (don't understand to what extent), create and edit HDRI maps (sounds kinda cool),render and export HDRI maps, has a hair and fiber lab, batch processing, and renders normal maps.
Studio: $899 USD. Renders up to 46,000 x 46,000 pixel images all of the above features, but also includes pixel script, animation ability and animation presets.
I've been told they have occasional 40% off or more sales around holidays, unfortunately I've missed all of them, I'd like to get the pro version which appears to be the best bargain. But only if it's around $180-$200, as the ability to create and export HDRI maps would great, hopefully I'll eventually catch a sale.
Genetica is only available for Windows... No Mac versions.
But that's not all from Spiral Graphics (makers of Genetica)....
They have two free programs available that are very, very useful...
-Genetica Viewer: http://spiralgraphics.biz/viewer/index.htm
Viewer will render out any of the couple hundred free presets from the Genetica Texture Pack in up to 2048 x 2048 resolution, as well as effects maps like bump and specular.
It's free and extremely useful, so why not just pick it up and try it out.
Wood Workshop:
http://spiralgraphics.biz/ww_overview.htm
Renders out any of around 100 procedurally generated wood texture presets in up to 3000 x 3000 pixels... And it's free.
As with Genetica, Viewer and Wood Workshop are Windows only.
And Lastly, not a program, but a great texture resource...
Textures.com (formerly CG Textures): http://www.textures.com
A collection of thousands of photo textures in seamless and non-seamless varieties... There is a free membership which allows for good, but small- medium resolution images and a premium version you pay for... It is "credits" based downloading and with the free version you get 15 credits per day... Depending on the credit value of the image (based on resolution) that could be four or five images per day... For professionals who need access to dozens of images, the premium plan would make more sense.
Hopefully this information was useful to someone.