Basically, your goal should be to lose as much fat as possible while keeping as much muscle as possible. This is accomplished the slower the better. I personally don't like to see guys lose more than a pound a week, although some may lose more & still not look like a concentration camp survivor at the end of the rainbow.
Also, I don't think it's all that safe to jump straight onto this or that "name" diet. For example, for decades, thousands of bodybuilders have done well on thousands of completely different diets. You take the top 20 guys, & they're all on 20 different diets -- and that's the way it should be, since everyone's gonna have a different response to protocol.
I've debated the holy **** out of the Cut Diet concepts with Chuck & Mark, and we're still friends - we just don't agree on carb placement.
For your 1st contest, I suggest that you keep things as simple as humanly possible so you know what changes to make for your subsequent contest (if you decide to do so). In the beginning, if you have about 15 lbs to lose, give yourself a minimum of 20 weeks to prepare. I don't think it's a dumb thing for 1st-timers to do a dress-rehearsal type of peak a few weeks before the show to find out what exactly your upper & lower thresholds are for carb intake, etc, not to mention what those thresholds are for looking cut but not flat as a pancake.
You can get all kinds of advices from this person or that, but in the end, you have to pay the most attention to what's going on with your own physique.
There's a brutal scarcity of good information out there on the specifics of precontest dieting, but here's one of the few done by Layne, not sure of it's his latest:
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Also read Joe Klem's stuff:
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Good luck. Remember that individual response overrides all outside advice.