One thing that can help with harmonic mixing is, when you have a 2-3 song combination that truly makes sense and is a crowd-pleaser, prerender it as a mashup. T

One thing that can help with harmonic mixing is, when you have a 2-3 song combination that truly makes sense and is a crowd-pleaser, prerender it as a mashup. Then you can audit ahead of time for train wrecks, and mix the final product in (harmonically or non-harmonically) with only a couple measures or beats of overlap. Not to mention that this can build a lot more hype as an individual release. Producers like 3LAU and The White Panda use this strategy to great effect.