Just my strategy, feel free to take inspiration if it seems feasible for you. I understand I got lucky here and there, and that some of what I am able to do with time management is not possible for everyone.
A lot of the premeds at my school go with a strategy that I think is garbage. They take out a list of ECs that are 'requirements' like you said with "research, clinical experience, clinical/nonclinical volunteering, shadowing, clubs". They find an activity or two for each box and start doing it all, or sometimes spread over 3-4 years. They burn out, sleep very little, eat little to nothing or all junk, and are demotivated 2-3 years into it. I think this sucks. The way I saw is is that, rather than checking boxes for clubs and stuff, adcoms would rather see that I cultivated the skills needed to be a good medical student; they'll make me a doctor when I am there, right now I need to learn and demonstrate skills a good med student needs. What are these? leadership, compassion/empathy/servitutde, team player, good communicator, life long learner, familiar with many cultures and life experiences, familiar with medicine and what they are getting into, comfortable with hypothesis based research. I found activties that both 1) helped me cultivate and demonstrate these traits and 2) were things that I enjoyed so that it was actually fun to do them instead of more work.
Side note, and underrated part of time management is making sure you don't burn out personally and still have motivation to do everything. Something I tried to do, for example, is to avoid doing any work after 7:00 or 8:00 p.m. I use that time to play games, watch basketball or relax and it keeps me fueled up to keep working the next day. I found that beating at something when you're just not making any progress is actually counterproductive and it contributed to maki g the stuff you do feel irritating and useless.
I found activities in freshman and sophomore year that I enjoyed and stuck with them.
1) clinical: found a job as a tech in a clinic at the hospital that does small procedures. One shift a week, Saturday morning 4am-4pm. I get 12 hrs clinical a week, no interruptions during the weekday and I am hope in time every Saturday to catch a game or get an early dinner w fam before bedtime. Sunday is free to do whatever. The sacrifice? Can't really take weekend trips, and waking up once a week at 3 for a 12hr shift is hard, but residents do this and much more so it's almost like I'm priming myself LOL
2) research: this one is harder. I found a clinical data research group and collect data w them, go to a zoom meeting every two weeks or so. All work from my computer, at home, on my own time. I mostly do it during my commute (I have a privacy screen on my laptop so no patient data is visible and sit at the back of the bus!). About 5-10 hours a week. Also applying for a summer research internship so hopefully I get about 250 hours of intense bench research.
3) service and empathy: a good clinical job helps, esp if it's with a more challenging or underserved patient population. I also found a local food back affiliated with a garden program. They send out a sign up every month, you choose which shifts you want, and I can choose which days I wanna go. I do about 15 hours a month, and it's a very fun environment which makes me look forward to my shifts. It's also during the evenings so I don't interrupt class schedules. Also do a LOT of service at my local house of worship, but debatable if I include that.
4) communication and experiences: work as a writer for a student group and do a lot of interviews with different people for different projects. I set up zoom calls w them on my own time and write on my one time. Very flexible, and have had so many eye opening conversations.
5) leadership: I did student govt, which is generic, but wasn't a fan and left after a year. Instead, I found an intl stem org I liked the mission of and joined first as a journalist, worked my way up to a development officer and am now president. Took 3 years of work. However, bc it's int'l and student run it's ALL virtual. Again, everything from home and my own computer. Very flexible, and awesome leadership and team work skills.
6) shadowing: cold email!! I set up shadowing during breaks and holidays. The hospital is one of the few places open when the rest of the world is relaxing. Yeah I lose a day or two of vacation but it's so easy to set up a shadow day in a clinic on like Dec 23 or Jan 4 or something when most other students are still sun baking on Cancun. I still get a good week and half of vacation!
I do a few other things, some seasonal and some regular. The point is that if you plan carefully, you can engineer a schedule that is very conducive to you enjoying yourself, being productive and not burning out. Find opportunities that are virtual, or once or twice a week only. And do things that interest you! Makes it seem less like a burden and work. Don't run after pubs either, but if it means a lot try for a summer internship somewhere one year and try to get a pub out of that. If you're a good writer join a think tank or something, or publish poetry idk what you're into. And it's not all about checking boxes, it's about showing you can be a good medical student. I'm no adcom, but if I was a med student I'd much rather have a classmate who majored in wine tasting and grew grapes to donate to hospices or something rather than a gunner premed with 628262 research hours and 19 first author papers each in nature, cell and NEJM. Nothing wrong w the latter, but the former is a cool person who will probably make a great med student.
