I don't know exactly what you mean by "docket", so I am just thinking of it as a faded document. Since you just want to make it easier to read, I am assuming that color reproduction is not important. I'm also assuming you are trying this on (or have access to) a Xerox style photocopy machine. I'm also assuming you are not super familiar with photographic techniques and photographic lighting. [I'm assuming a lot but I think I need to in order to provide an answer.]
I wouldn't give up with the photocopier just yet. Using a camera and Photoshop does give you more control, but if you're not experienced in how to use those tools then you might get better results with a photocopier. Anything you would do with the camera/Photoshop is just mimicking what the photocopier would do. (Or vice versa, depending on how you look at it.) But it would be much quicker to try a few things on the copier.
Recovering document detail with a photocopier
First, I would turn the brightness down (darker) on the copier until you are not seeing a pure white copy. Then try turning the contrast up. If that makes everything white again then try lowering your brightness further. If you get stuck making pure white copies with a low brightness setting then turn your contrast back down. If they are still pure white then try changing the resolution setting on the photocopier. If you still can't get it then you'll have to resort to using a camera.
Recovering document detail with a camera
If you have resorted to using a camera, you want to output of the camera to be as close as possible to your end goal. (In other words, try to do it all in-camera without needing to Photoshop it afterwards.) You can try using the flash, but I suspect you will get better results without it ... as long as you have enough light in the room. If you need more light you can trying moving the document over near a window, moving it in a shady spot outside (if it's not to breezy) or even a sunny spot outside. (There should be plenty of light in the shade though.) However you get your light I would underexpose the image. [This is actually "exposing to the left". Exposing to the right is good for getting better detail in the midtones/highlights, but here we are trying to get detail in the shadows.] So look for the "EV" (Exposure Value) setting (there may be a bar that looks something like this:
- | | | | + ) and nudge it over to the "-" side. That's the equivalent of turning the brightness down. Then look around for a contrast setting. (you can google your camera model or post a question about how to adjust these settings for your camera model) We're trying to do the same basic thing here that we were trying to do with the photocopier.
Recovering document detail with "Photoshop"
If you've made it this far then you're pretty desperate. Try "throwing a hail Mary" ... use the auto brightness and auto contrast. If that doesn't work, you’re going to have to manually make the shadows darker. This is easily done in Picasa with the “Shadows” slider. In Photoshop there are exactly 42 ways to do this. Explaining them all in detail would turn this into a long answer. Nobody likes long answers. cough So I'll just list off the adjustments I would play with, in the order I would try them. I'll let you do your own google searches to find out how each feature works.
- There may be 37 other ways to do it, but I don't what they are.
If you still can't get the detail back
If you spent all that time in Photoshop and you still don't have what you need and you still haven't given up ... go take a nap or something. Chill out. Then maybe try tracing over the words with a black pen/sharpie. Because at this point, you are that desperate.