Online metronome
Turn the knob or tap the tempo, then stomp the switch. The speed trainer nudges you faster every few bars, which is the quickest way to build clean speed.
Set a tempo you can play cleanly, start the click, and raise it 2 to 5 BPM at a time. Most players learn a new part at 60 to 70% of the record's tempo first.
Stomp to start. Delay at this tempo: quarter ms, eighth ms, dotted eighth ms.