How do people use the last summer before submitting your medical school applications?

Get work experience/volunteer or work part time as a HCA.
Start learning anatomy.
EDIT
I know that I have had the hate before regarding the suggestion of starting the anatomy journey early in the summer before school starts but the people who have done this will categorically fly through first year because having good or even excellent baseline anatomy knowledge before you even get in the door very much eases your initial workload and hence potential stress. It also allows you to focus on your pre-clinical years which are very important later on.

Thanks. That's useful to know. I've been volubteering in a locl hospital as a ward helper since August this year. I also have a part time job during the weekend. I haven't had any work experience placement, but am trying to find one. Could you recommend any books for anatomy?

See if you can find a second hand (and hence very cheap) older edition of say Gray's anatomy for students. (not the regular version of Gray's anatomy).
Read through the chapters steadily without getting into too much detail. At the same time, find and download an anki anatomy deck to work your way through. Maybe try to do 10-20 new cards a day only. If you started now or in the summer holidays you will be well on your way into anatomy before September next year.

Hi everyone, I am currently a S5 (Year 11) student in Scotland. I want to apply for medicine 2026. I wonder if someone can share how you plan to use the last summer before submitting your medical school applications.

Get a job in a care-home.
Nothing else will show you exactly what front-line healthcare is all about.