So you have your tracks ordered properly right?
You might think so, but this one tiny hack/trick is awe inspiringly good and incredibly simple.
Create an empty silent track, use audicity or the like to do this.
Drop this empty track into a playlist and separate the tracks that work really well together with this empty track.
It'll look something like this.
I know right, it's epic, it's simple, and visually it immediately creates groups.
Rekordbox/Serato trick to grouping tracks

──────────────────◉──────────────────
I◄◄⠀▐▐ ⠀►►I ───○ 02:05 / 04:10 ᴴᴰ ⚙ ❐ ⥂
Autism is a neuro-developmental condition characterised
by difficulties in social interaction and communication,
as well as restricted and repetitive behaviours or interests.
The video where this idea came from.

──────────────────◉──────────────────
I◄◄⠀▐▐ ⠀►►I ───○ 02:05 / 04:10 ᴴᴰ ⚙ ❐ ⥂
Autism is a neuro-developmental condition characterised
by difficulties in social interaction and communication,
as well as restricted and repetitive behaviours or interests.