Tips for texturing... I just can't seem to get it.

I just don’t understand how they do it. I know the employees for big companies are extremely experienced but I’ve been doing texturing and modeling for years and just can’t seem to come close. I’ve included some pictures at some textures I’ve been trying to reproduce for an environmental piece of mine and I just don’t know how to get close to it. Are they using actual pictures and then editing them from there? Are they free handing everything? I just can’t get close. And you can easily tell they aren’t using any normal maps to add any detail and there is no shading at all.

THese are hand painted Textures , mostly done in Photoshop. Search the net and you’ll get some very good tutorials (Polycount.com is a very good resource for all 3d related stuff ). They also heavily rely on AO maps for those shaded region.
If you look closely , the artists has applied several type of Dirt , grunge etc to give it rough worn out look. you can also do the same.

Upload your blend, lets see what we can do for you.