I didn't have a tutor, and I hated every moment I had to study for ancient, but I was very motivated. This was because I knew unless I got a very high mark the scaling would be terrible, and I had an awful teacher who really did very little.
Most important thing is HAVE LOTS OF HISTORIOGRAPHY. My HSC exam responses were littered with quotes from academics, many of which contradicted each other, showing how I was aware of the debates. In order to get these, you need to go beyond the notes teachers give you and access journal articles and various books from the library. Once I had these I'd scan them and get the general idea of what the author was saying, and then make a few notes and record important quotes (the walls of my room were covered in quotes, which was slightly scary as I could never really escape the HSC).
I also answered every past HSC question and then went through what I wrote and highlighted important sections, and then just went over them again and again, writing things down as I went along. For Sparta, we had an assessment task where we had to make notes with historiography under each syllabus dot point, and so I put those 25 pages in a folder and just read over them occassionally. This was so effective I also decided to do it for my historical period, and it worked wonders. Having everything in a folder just makes things much easier to handle, especially for ancient where I had over 100 pages of summary notes.
But yes, don't stress too much (though a little can help as it motivates you). So yes, that's how I got my mark, and believe me, it's not impossible. During the year I was basically most concerned with preparing my notes for the final exam, because I knew that was what was important, and didn't really revise too much until Stuvac (in my 1/2 yearly my evil teacher gave me a mark of 60%!). But yes, during the holidays before the exams, with all my notes (filled with really good historiography) done, I was able to spend about 4 hours a day just revising for ancient. And really, when you think about it, that isn't that much and is realistic. Don't become a recluse like the girl who topped ancient in 2002 (she made her parents lock her in her room and she studied 14 hrs a day), it really isn't worth it. But if you want a mark above 95 (and subsequently avoid the poor scaling), there's what you have to do.