Rhythm: Metric Modulation
These are metric modulation exercises you can practice with a constant metronome. The upper line shows how to prepare for the new tempo. These will be the new quarter notes. The lower line shows what the metronome will sound like in the two different tempos.
Pick a simple rhythm or play walking bass and prepare the new tempo in the last bar before the change. Try to maintain a steady tempo over the odd metronome.