The Basics:
Watch what they look at during the exam. If they don't check it, don't mark it down.
Conversely, if they spend more time than usual on one system (an extensive neuro exam, for example), document the CRAP out of that system.
Listen to their wording. If they phrase an exam finding or a question in a particular way, use that phrasing. There is particular meaning to some phrases, such as "thunderclap onset" or "worst headache of my life"
- Once you've learned some of these key phrases, look for ways the doc is trawling for that info without explicitly saying it...for example "when was the last time you had a headache this severe?" is often used not only for timeline info, but also because if the patient supplies an example, you've automatically ruled out "worst headache of my life" without setting the patient up to over-dramatize it.
Write down times for everything - calls, procedures, first time you see the patient, etc.
Learn the doc's normal discharge instructions and have them ready to go before they ask. If almost every abdominal pain discharge gets the same instructions, put those in as soon as you get an abdominal pain patient...odds are that the only time they won't need it is if they're being admitted, and then they won't print anyway.
Extras:
Listen carefully if the doc explains their plan to the patient. If, while you're in the room, the doc tells someone that they will be getting an ultrasound and basic labs, and then you notice that an ultrasound was never ordered, it is perfectly reasonable to ask them "so you told Mrs. X that we would be getting an ultrasound, are we still planning to do that?" or just "so, what are we looking for on Mrs. X's ultrasound" if they are touchy and you need to avoid sounding like you're pointing out an error. Paying attention like this can save hours if it turns out that the US was ordered, but not the labs, or vice versa, but the lapse gets overlooked until they're ready for discharge after getting half of their stuff. You'll also (occasionally) see them enter orders backwards...the CT on Mrs X and the US on Mr Y, and catching them early saves time and money.
Pay close attention to details such as hysterectomies, Hx of kidney disease, etc. A lot of studies require other tests to precede them - women of childbearing age, for example, almost always get a pregnancy test before a CT exam. If you pay close attention when filling out the SHx portion of the chart, you can sometimes point out 'hey, Mrs Y had a hysterectomy' when the nurse or CT tech tells the doc they won't go until the blood test comes in. Same with contrast studies and kidney failure...it's just easier to know it up front.
If your doc prints a script, go grab it for them without being asked. Most of the time, you can hand it to them before they remember they wanted to go get it from the printer.
Most of it, though, you just have to learn on the job by eventually figuring out each individual doc's preferences and style. It's kind of a crappy trial-and-error process, but by the end it can feel phenomenal.