Academic 7 is very achievable. I have reviewed (self study) only for like 1-2 weeks, about 2-3 hours a day. I'm a bit good in analysis, numbers, etc. but i admit that my english proficiency is only mid/ above average at best. I only stick with cambridge 6-7 and listen to some podcast/ youtube vids while travelling in the mrt. Using cambridge i have only managed to get 24-28 scores/ 40 for listening and reading. Actual exam for listening/ reading is a bit easier than practice set. For writing i focus only on my own created paragraph outline and memorised some adjectives/ verbs and few idioms. For speaking, i dont have any strategy but bahala na, since nagsurvive naman ako sa SG for 4 years speaking the language.
Bottom line is practice/ preparation is only half the battle. I've learned after taking many exams during my career, that strategy and mental attitude during the exam day is also equally important. Being relax and having proper mental focus is helpful. Pass or fail, lets get it on! Dapat tanggalin na yan mga takot or kaba na yan kung meron man. For me, Nescafe/ redbull in can in the morning also helps lol.
Ofcourse, people have their own different ways of preparing for exams. So find out which hour during the day nakakaabsorb ka tlaga ng infos, even the location (study area). Ako din alam ko, mas natututo ako through self study kesa live lectures (this one i knew since my college days). So know yourself, prepare, relax and pray and go. You can make it.