I’m moving into a darker, almost movie soundtrack vibe with Ex. 3. I used the b5 (Db) to give it a more weird and sinister feeling. The tritone is also prevalent in a lot of electronic bass lines due to its darker and mysterious feeling. It leaves space for more atmospheric things to occur in the music.
I also played the phrase in a somewhat rhythmically complex way, leaving space over the barline and inserting movement in unusual places. You have to have a strong sense of the beat to pull this off. A way to approach this is to take a rhythmic phrase and keep moving it around inside the four-measure phrase. The Swedish metal band Meshuggah are masters of taking an ostinato and twisting it until the phrase comes around again.