Count the beats in your head, tap the 1-2-3-4, 1-2-3-4 using your feet and you’ll soon be able to judge timing naturally. In the majority of EDM songs you’ll hear tiny things happening in the music every 4 or 8 bars, these are typically where you’d do the big transitions in a mix, e.g. a vocal drop or switching the bass from one track to another. Once you get used to the rhythm of the songs you will hear the drop points coming even if there aren’t any distinguishable changes happening in that particular song. I guess it’s a case of re-wiring your brain to listen to music in a different way.
For a quick fix, use the ‘time remaining’/ ‘time elapsed’ counter, practice the mix until you get it sounding good and then remember where to drop it in using the counter.