Practice makes perfect. I wouldn't worry about it unless you're finishing residency and are still having problems getting out on time. Just remember, whatever time management skills you internalize and hardwire, will carry over to attendinghood. The exact same goes with bad habits. In residency, we weren't allowed to leave without all admitted pt's notes completed. I managed to complete most of my notes by the end of my shift, but honestly it wasn't until my first or second year out that I transitioned to completing 100% of my notes by the end of my shift. I think it's incredibly sloppy to leave work on admitted pt's without the note completed. And we wonder why consultants and admitting docs place more value on the nursing notes than ours...
By and large, the biggest issue having a deleterious effect on time management in residency is the same thing people do as an attending and that's feeling the pressure to pick up pt's on the tracking board without a name on them. You therefore sign up for way too many people than you can comfortably see, and it kills your metrics as well as your time management putting you perpetually behind during your shift.
The second thing is being able to identify bottlenecks and hurdles to disposition within the last hour and a half such as a particular lab hasn't been collected, CT hasn't been done, US or MRI pending..(have they been called in?) and addressing these early, as well as identifying within your last 30 mins the pt's that are failed dispo's with SOS written all over them and no way that you can possibly finish everything even when staying an hour over your shift. (You got a dimer that was +, sent to CTA and they are too fat for good vascular opacification or the contrast timing was off or both and the study is worthless and now you are considering VQ and they are just calling them in 5 mins before you are supposed to leave, etc...) For the failed dispo pt's, put your pride aside and just sign the pt out if possible. I realize that in residency, sign outs should be much more common, but for practices where it's not as common (i.e. RVU based), I think it's important to be able to sign these out to the oncoming doc and get out on time. I've seen some of our new docs stay 2-3 hours after a shift to finish up a single pt that they are too prideful to sign out and nobody needs to be stuck at work that long after your shift. Help your colleagues get out on time and chances are they will help you do the same.
The third thing I commonly see is a personal decision and that's whether to half finish your note in order to see more pt's in your shift, with the plan on leaving on time but having to chart 2 hours after your shift. I feel really strongly about this one and my CMG doesn't pay me to chart and I refuse to chart on pt's after work. I may not be the fastest, but my avg is still 2.3 pph and I have 100% charts completed by the time I leave. I'm ok with that as I am much less stressed when I leave work and don't have to worry about not being able to recall small details 6 hours or a 1-2 days after my shift.
Long post, but the short of it is... just do your best and find what works for you because it may not work for everyone. Whatever system you utilize, get proficient at it and chances are it will serve you well after residency. I would encourage you to aim at finishing your admitted pt's notes at the very least by the time you leave (or by the time of admission if you can do that...) and whatever you feel comfortable with regarding the rest. You'll get there.