I would suggest taking a year to get some research experience in. One year will make you ridiculously more competitive. But - anyway, back to the advice actually requested.
I am prepping to take the exam the 27th of this month, so I can't exactly say how successful my method has been thus far. (I did take the practice test yesterday and got in the 70%, though I am gunning for 90th) Hopefully you have a good basis to go off of from undergrad. First I would go through the ETS outline and see what topics you know you need work on. Right out of the gate I knew I need to review enzyme kinetics, motor proteins & cytoskeletal elements, ECM components, photosynthesis and signaling pathways (this is just the very beginning). Tackle the things you know from your classes you either didn't understand or forgot the second you walked out of the exam. I read up on these things and watched lectures.
I'm sure you've seen recommendations for readings, Alberts Molecular Biology of the Cell, Lehninger Biochemistry, whatever else people are recommending for genetics (I've found from internet, Alberts, Lehninger and youtube, you don't really need a genetics text). Don't get too caught up reading from cover to cover (you're short on time anyways). I'm wicked dyslexic and ergo a slow reader, so I primarily watch lectures and supplement with text, instead of the other way around.
Do as many MC questions as you can possibly find in scouring the internet (PM me with your email and I can email you what I have found)
Study as much as you can, many people take 3 months to study for this (not like 12 hr study days, but with work/school), but in your case you only have month.
I started making a playlist of helpful youtube videos if that helps( https://www.youtube.com/watch?v=I9Ar...jxS9DMaMnTLoxo ). For biochemistry I really like Kevin Ahern (played back at 1.25-1.5x speed, use a youtube to mp3 ripper and open in VLC). He goes into the depth needed, and will often pop a cell biology relation that is relevant to the exam.
I almost forgot to mention the methods.. Don't forget to study this... This is where research experience really helps you.
Best of luck to you,