For general relaxation, every 3-6 weeks often works well: often enough to stop tension building up, spaced enough to feel the effect.
For sport or recovery, weekly or every other week can help in an intense period. Afterwards you can space appointments out again.
Listen to your body. If tension returns quickly, or you stay “loose” longer, adjust the rhythm. Via My appointment or your account you can rebook the same treatment in one click.