i honestly didn't do many whole practice papers (hot take lol), i just found them inefficient and huge causes for procrastination. i also did two major works.
for my majors, i made sure i was consistently working on them as well as my logbook/diary (as you can get marked on these internally depending on the subject) i literally found whatever time i could to come into school to work on them, there was actually a period of a few weeks where i was going to my visual arts classroom every morning before school for an hour just so i could work on my VA major. this is probably something you should discuss with your teacher. being able to work on my major whilst having my teacher there was really beneficial as having their feedback while you're working really streamlines the process imo. as well as this, take advantage of your time in class when working on your major, don't use it to procrastinate or talk to your friends, if you do that you'll end up like a lot of people, a few days out from submission, totally lost and nowhere near completion.
as for practice papers, i usually did individual sections timed, with a weighted pen (my english teacher told us to start doing this at the start of y11 lol) or i'd do essay plans so i wouldn't be sitting at my desk for 3+ hours. for example, for ancient history i did a lot of essay plans for questions that were between 10-25 marks, or i'd do a 45 minute section, in 40 minutes. i did this a bit through the year, but especially in the lead up to exams, and i ended up having like 15+ minutes at the end of my ancient hsc to edit my entire paper because i trained myself to complete sections in less time than allocated
for english advanced, i chose my quotes and themes very early on in the year, wrote a 'staple' essay (basically just a broad essay that could be moulded to questions), then wrote practice essays throughout the year based on the 'staple essay' using practice questions, and once it got closer to exams i focused on doing essay plans just to help me with the skill of adapting my themes and quotes to questions. my essay plans for english were typically an intro, 3 paragraph ideas + quotes and short analysis, and a conclusion.
i wouldn't really recommend working at recess or lunch, i only really did that if i had an exam the next day or something. use that time to relax, the last thing you want to do is burn out before trials and then not be able to make it through the rest of the year.
this is just what worked for me, so if you feel like doing whole practice papers then by all means go for it, i just personally found it to be really inefficient and tiring to sit down a few times a week, for 3+ hours to do an entire paper lmao. i honestly think it's way more beneficial to your cognitive performance to study in a way that is sustainable, rather than try to do that 'grindset' 10+ hours a day shit LOL. regardless, i hope i could be of some help!!