I want you to understand that in order to build, maintain and sustain muscle we must give it a reason to stay or grow. That's the nature of a lifters career, every heard the term "use it or lose it"? That is exactly what we are doing here. The training that built your body will be the training that you will use in order to lean down. I recommend that you stick to compound movements as the main focus along with training in both rep ranges of hypertrophy and strength.
Too many trainees and athletes are quick to overlook (and sometimes forget) about the bodyweight workout. Even so, you can become very strong when training with just your bodyweight. Bodyweight training is all about the basics and the truth is, no matter how advanced you are, your body will always fall back on its base level of strength. Your overall bodyweight strength will always serve as the foundation and bridge to your other strengths.