Normalization and Dynamic compression
The best way is to put your fingers on the masters while listening to the final mix. Keep it just kissing the red. You got 16 bits, use them, but use them tasteful
This is so much wrong I don't know where to start.
#1, you are always using 16 bits. Those bits are not sequential, and do not describe 16 different levels for the volume -- they describe 65,355 levels. Using your entire meter doesn't mean your sound has greater dynamic fidelity and in fact means the opposite.
--------extra special note from me: I am an IT consultant with 18 years' experience and a programmer. I am not guessing about this. EVERY SINGLE sample of your waveform is a value between 1 and 65,355 (or -32,000 and +32,000 if you are using signed integers). You are NOT going to get "more bits" by turning your volume up. You will still have 16 of them, and all of the values will be used for something.
#2, "kissing the red" is not what you are after. One thing I don't see people much make note of is that compressors and limiters have two functions, one of which is to knock down the peaks, the other is to bring UP the valleys. You're far better served figuring out what sounds you want to "auto make-up" or whatever your plugin does, and bring those up to the level of your recording.
If you aren't sure about this, and you have say Reaper, put the compressor on a track, and then turn on "auto make-up" or use one of the limiters that has a floor as well as a ceiling. This has a big impact on sounds and doesn't clip your meters, which is always, always, always a bad idea.