I get asked about mix tricks a lot. There seems to be a belief amongst students that if they just can learn a few more tricks, their mixes will somehow jump to the level of the best mix engineers. Of course, there are a big problem with this. Mixing is a craft, not simply a collection of clever tricks. More importantly, the best mix tricks in the world are still context sensitive.
So, here is the ultimate mix trick: the trick that isn’t a trick. When mixing, focus on what’s actually there on the tracks, identify a problem, then fix the problem. Any mix trick is designed to solve a problem in a mix. If the tracks at hand do not have that problem, then the mix trick is useless, or worse, it may actually cause other problems.
For example, I know a lot of mix tricks to help get a kick drum to “play well” with the bass guitar. I might do some filtering of the two tracks, or duck the bass under the kick hits, or (to me, better yet) use an expander to make the bass hit a dB or two harder during the kick hits. But none of these things are needed if the raw kick and bass tracks I was asked to mix already work well together. Since I mostly work in music, my focus is usually musical. Rather than starting by thinking about the tone of the kick and the bass, I ask if the groove of the tune is solid. If it is, then there is no problem. If the low end of the groove is a little loose, especially if it seems to come and go, then that is the problem. Then, we go to the bag of tricks.
Know when to use your tricks. Identify the problem, then solve the problem.