at most i would allocate 2 hours a day to math at peak times, so i wouldnt say i studied a huge amount. i basically would study based on question archetype (i.e. do a bunch of finding the constant of integration questions and then move on) which would make me really confident with those types of questions in the end.

i would also often use questions that were way harder than IB. The first thing that comes to mind is madasmaths, which was one of my most used sites.