Week 1: Find out where you are
Take one full-length practice test under real timing: two Reading and Writing modules of 27 questions in 32 minutes each, then two Math modules of 22 questions in 35 minutes each. Don't pause the timer.
Then sort your misses by skill, not by section. You're looking for the 3 to 5 skills that cost you the most points. That list is your plan for the next four weeks. Register this week too, so the October 23 deadline doesn't sneak up on you.
Weeks 2 and 3: Fix your weakest skills
Four or five sessions a week of 30 to 45 minutes, each on one skill. Do 10 to 15 questions, and for every miss, read the explanation until you could explain it to someone else. Retry old misses at the start of each session.
Start with the skill that costs you the most points, and the one that shows up most. On Math, algebra and advanced math together are about 70% of the section, so gaps there matter more than a gap in geometry.
Week 4: Check your progress
Take a second full test on a new form, not one you've seen. Compare skill by skill with week 1. Keep the skills that improved in a light review rotation, and move the ones that didn't to the top of your list.
Weeks 5 and 6: Sharpen, then rest
Week 5: keep drilling, and add timed sets so pacing becomes automatic. Early in week 6, take one last full test, then only light review. Two days before the test, stop studying new material.
The night before: check your admission ticket and ID, charge your device, and get Bluebook set up on it. Then sleep. Rest does more for your score than one more practice set.