Use an upright bass (common in jazz-sampled hip hop) or a subby synth like a Moog .
Aim for a range between 80 to 100 BPM . Lower BPMs (80-88) often provide a better "groove" and "drag" for that classic 90s feel. boom_bap_type_beat_piano_instru_rap_old_school_...
Place the kick on the first beat, with a secondary "ghost" kick or a shifted second hit to create a syncopated, swinging rhythm. Use an upright bass (common in jazz-sampled hip