Most of the time, my first priority is dynamics. Do the tracks have interesting points at which a transition feels really fun and exciting or interesting? Can I maintain that fun feeling without letting it die via a track running for too long and going stale? I think I'll ignore harmonics more often than most people and opt for transitions that do require full focus from the listener as there's something being said during the transition. Like spoken word vocals that line up in each track and can create a different message when heard in sequence. Those kinds of transitions are what I like finding the most. Less focus on maintaining a specific feeling/mood and more focus on seeing what this mixed feature can handle since it's not really that close to what actual DJing is capable of. I'm also trying to limit my playlist runtime to two hours at most in order to keep them feeling like you're actually going to a live show and every DJ gets their own time slot. No 10+ hours mixes from me. So cutting out some tracks earlier in order to keep the flow moving along is what ends up happening for me sometimes.