What I want to do is to texture it with a dirty wood texture, which I’ve done.
I want to make a few versions of the same crate but with different textures, such as a clean wood, a dark wood, a painted wood texture.
Would you just duplicate the low poly mesh a few times and unwrap each one with a different texture?
Or, would you create another blender file for each one?
Or, could you just create 3 or 4 different materials and apply the style you want to the crate before rendering / exporting?
I’d put all your textures together into a single image, with 4 quadrants, and move the UV coordinates of the various objects according to which look you wanted. that way you don’t have to deal with multiple images, or multiple materials at all.
Duplicate your crate and its material, rename both, paint a new texture, replace the new crate’s Diffuse material node texture with your newly painted texture, repeat.
If you want to use one large texture for multiple crates, after duplicating the crate, move it to its own UV space in the UV/Image Editor and paint one texture.
There’s no need to use individual Blender files for each crate. There are reasons why you would do it this way, but, I’m doubtful it matters to you at this point (memory usage, sculpting, normal mapping, organization due to some file structure a director or programmer wants, file or folder organization outside of Blender instead of inside, etc.). For simpler objects with less detail, just do everything in one Blender file.
All of this said, it depends on what you want to do with the crate in the end. Game or film? Who’s looking at it? How far away from the camera are they? What texture size limit are you working with (either your own set size or the director’s/programmer’s). Are you concerned with CPU/GPU/RAM optimization?
What are your intentions? There are many advantages and disadvantages to everything you’re doing and you’re not going to know about them unless you either experiment, practice, research, or work for industry-standard companies.
After figuring out that goal, it will dictate everything else you do in the process.
