Normally for purchased items you apply textures via the Pose folder while in the pose room. You can create a sub folder in your poses for a set of favorites you've created for a particular outfit and save copies there. In Poser there's also the material folder which if it's an item you purchased you could see that the vendor put the textures there to load. If you are using a product that is just a material set that are purchased you pretty much can do that from the materials folder but have to pick and apply every piece. Sorry if this isn't worded very well... To save a set of favorites, have a scene with only the clothing (or item). Make your changes via the materials (or material nodes room). Pick your sub folder (I call mine Mine, then a sub folder for the particular item) in the Pose folder. Add the item to your Pose folder via the + library button.

The dust settled, thinking "what a fine home, at least for now" not realizing that doom would soon be coming in the form of a vacuum cleaner.