Watch for “the wall”: Marathon runners hit a wall somewhere around the 20-mile mark. Mixing engineers experience something similar: After a point, mixes don’t get better, they just get different. Learning to recognize when you’ve reached this point is crucial to improving as a mix engineer. Unlike runners, however, engineers who hit the mixing wall should stop what they’re doing! Take a break. Or better yet, consider that the mix might actually be finished!
Try lowering the volume: Along with checking a mix through different speakers, it helps to listen for elements that jump out at different volume levels. In particular, spend some time with the mix turned way down. Thanks to equal loudness contours, our ears perceive bass frequencies differently at low volume, so mixing quieter can make it obvious when your bass levels are off. It also forces you to listen a little closer!
Skip the cheap reverb: If you have a choice between a low-quality reverb or no reverb at all, leave the track dry. When it’s not used as an obvious effect, we generally add reverb to restore a sense of natural space to close-miked tracks. However, cheap reverb sounds unnatural, and your listeners’ ears will sense this immediately. (Read more about why you should avoid cheap reverb.)
It’s easier to mix well-recorded tracks: Trite as it sounds, tracks that are recorded properly are easier to mix than tracks with problems. Any mix will only sound as good as the players, instruments, and equipment used to record it. If you’re having difficulty mixing a particular track, consider re-recording it …