Is there a best practice for increasing gain on your master?
It should be done with hardware.
Of course you should always be mixing with what you want your end levels to be in mind, but when you do want to raise your track a few db's should you do it through your master comp/limiter? If so, post or pre?
The signal that hits the master bus is constantly reaching different overall perceived resonance levels at various locations in the song. The compressor on the master bus is going to balance that out, hence lowering the perception of those resonances when they hit, while at the same time damaging the stereo image. So overall it does not serve the mix that much other than it can produce a little more balance to an otherwise too dynamic mix and in that way make it a bit more pleasant. You can add some broad stroke compression with the purpose of slightly balancing and reducing unwanted resonances and to create some separation between groups of tracks in the mix, by adding it to sub mixes.
The reason you want hardware compressors/limiters is to add that compression naturally on the signal. Generally you want to achieve as much of the final peak and rms levels as early as possible, meaning already during production and recording. Then at mixing you work on it more, volume fader riding and side chain compression are techniques that can help a lot but it is tricky to have to create all target peak and rms levels during mixing, it kind of becomes fake and does not work so well. You should achieve your peak and rms levels as a result of the recording process and then have additional compression mostly for tone character tuning, noise reduction and maximization of headroom utilization.
Or should I use some other type of vst? And lastly, does raising your master gain noticeably affect your tracks timbre? Sorry for the barrage of questions, like I said, I'm rather confused on the theory off all of this. Any help would be appreciated, thanks!
You should not use plugins. Instead, you should ensure you have great hardware with great headroom and are able to gently massage that signal louder with good gain alteration, EQ moves, compressors and limiters. It is all about achieving your target music while maintaining the natural properties of the sound. In that way you get the music through to the listener in an emotional way and that is what the listeners like.
It all starts with great acoustics at the input and the output. When you combine that with natural gain altering moves through volume fader riding, you get a good overall balance while at the same time achieve your music objectives. Then once you have the peak and rms nicely balanced, you can work with hardware to amplify and balance that what you like against that what you don't like. It sort of becomes natural when you work with natural gear. It is a tuning process that should be kept as natural as possible.
But because late time broad stroke compression can work to separate elements in the mix and can work to raise the overall resonance level (on complexity levels impossible on more isolated scopes), it is kind of an important aspect both during mixing and mastering. You will always find compressors and limiters are effects you at least want to try the material on. Much of really good work requires a good testing strategy, one should allow the magic to happen even when you cannot replicate it and even when you do not fully understand the inner workings of it all. Because of the natural behavior of hardware you can achieve highly resonant results, you get shifts between highly dimensional resonance structures forming out of it all when you play the mix. It's all about resonance.