Here are some ideas as to how to make it easier for you to stay on top of large legal translations in CAT software. It's the same with tech translations and anything else which just might be litigated. Or just might kill someone or run up huge damages. Obviously medicine comes to mind. And finance. But it can be anything, not only because of the subject but also and especially because of the intended use.
First of all, forget widescreen CATing unless you're positively certain that paragraphs stretching all the way horizontally are actually easier for you to manage than narrower and tighter, more densely packed boxes (preferably in a small font size). In Windows 7, you can just drag the CAT window to the left or right edge of the screen to make it take the left or right half of the screen.
If using your CAT on one half of your screen only, make sure you don't have a distracting wallpaper, such as a highly detailed photograph (like the nebulae from Spitzer which I used to use). Rather, go for a soothing medium green with a hint of blue, such as R 13 G 104 B 107. Okay, this is a bit more blue than it is green, but I wouldn't have guessed. It's probably close to 'cadet blue' and traditional Windows desktop colours. This:
Next, crank font size down. Down to size 12 on a huge >20'' monitor in 1920x1080 screen resolution. Larger fonts are easier on the eyes — too easy, in fact!
In essence, you're forcing yourself to pay attention and to follow details instead of just following the flow. Stuff that doesn't matter in literal or even marketing translation can wreck a legal contract or tech specification.
It depends on the eye, and 12 does hurt mine. But 14 and 16 makes me feel like I'm reading a novel or something, basically a literary mood which invites fantasy. Which is not what we want here. Better this little headache than the worse headache when you miss something that doesn't make much difference, ever, except in that one particular situation your client is or gets himself in.
If it hurts, you won't be dozing off.
You gotta read very carefully. The more slowly you can, the better. Naturally, this doesn't make you happy at six cents per word or something, you basically gotta charge some solid rates to make all this nitpicking pay for itself.
Use the CTRL+F a lot. If you have a couple of separate but related documents on your place, don't put things off until later. Just go and fix the problem you've just found in all other documents. Don't presume it isn't there. If you're sure it isn't there, still go check. It will take more than a minute of your time to set things straight if you miss something at this stage.
Don't make notes and put things off until later — unless you really are comfortable working that way, keep saving the notes in case electricity dies or your Windows decides to restart when you're away from keyboard. Better turn off any such automatic restarting, with or without prompt and wait — I've had the thing reset on me after leaving it unsupervised for more than 10 minutes. And make sure you actually do anything you put off till later.
Don't allow it to become an excuse and a hope that you just might forget and spare yourself the hassle. Just go do it. Like a good labourer. Because this is like physical work at a construction yard, but it still needs to be done. It will become easier and more 'native' to you as you force it to become a habit.
Oh, and just in case: challenge any presumptions and generally don't put things off till later anyway.
And keep track of everything you do.
As for specific things to look for, try to keep a list. If you end up correcting something or having a proofreader or client spot it for you, note it down, make sure you check for it specifically. Even if your checklist grows to be long, it's still much shorter than thinking about all those things would be if you didn't have the checklist.
You don't need to show that checklist to the client or PM or anybody else, so it isn't as potentially humiliating as the checklists you perhaps receive along with POs, some of which are pretty obvious or sound like patronizing.
Numbers. Always get the numbers right. Money, and phone numbers, and any other numbers. And measurements. Measurements along with units. And any unit conversions you want to or are expected to do.
Get the punctuation right. In some languages you are allowed to use optional commas to 'assist the reader'. So do. It will assist the reader.
Don't go high fantasy on the legalese. Subjunctives, inversions etc. have their place, but you often want to KISS. Just make it legible and transparent so that it's easier to revise (for you, among other people), update or follow. Or understand — if the reader is not a native speaker or college grad. Or a tired person. Tired translators, too, misunderstand and misinterpret things. And you might be doing just that right now as you're translating — if this is your eleventh hour or something.
By the way, don't hurry, and know your limits. Go to bed, wake up in 8 hours, resume. There are still only 24 hours in a day, you can't make more. Get some rest, you'll be more efficient and less error-prone. And your motivation will improve, which is crucial when you need to look at thousands of boring paragraphs scrolling down before your eyes.
Slow down and don't be too schematic. This is a bit challenging because you need to be just schematic enough to follow patterns and stay consistent — and simple — but you really need to avoid false cognates and other false, too easy associations. Watch your homophones. Try to have the entire scope of meaning of those words and phrases in mind, not just the one you supposedly need or the one you think the source has in mind.
Think about misunderstandings. Avoid them. Don't translate in ways which are open to misinterpretation. KISS helps, but don't overdo it. When you really go too simple, it no longer is simple. (Just like the 'plain language' which some drafters use and which makes sure nobody can understand the drafting any more and pinpoint the meaning.)
I didn't mention any specific words, but keep a list of them, particularly anything you might be prone to forgetting in your translations in general or the one project you're doing right now. Those will be different words from person to person and from project to project, so I won't cite any to avoid anchoring.
Just remember to CTRL+F the thing until it no longer exists anywhere (CTRL+H for 'seek and replace' in some other software).
Finally, you may want to read up on economics, healthy work habits (taking breaks, looking out the window every now and then, washing the coffee down with some water etc.).
And turn down projects if you aren't in a good shape or if the situation gets risky and you aren't sure you'll manage to set aside some time for contingencies.