It is best to wash with soap and clean water every day, if possible. Also:
wash your hands before eating or preparing food, after passing urine or stool, and before and after caring for a baby or someone who is sick.
wash the genitals every day with mild soap and water. But do not douche. The vagina cleans and protects itself by making a small amount of wetness or discharge. Douching washes away this protection and makes a woman more likely to get a vaginal infection.
pass urine after having sex. This helps prevent infections of the urine system (but will not prevent pregnancy).
wipe carefully after passing stool. Always wipe from front to back. Wiping forward can spread germs and worms into the urinary opening and vagina.
Sources
Burns, A. A., Niemann, S., Lovich, R., Maxwell, J., & Shapiro, K. (2014). Where women have no doctor: A health guide for women. Hesperian Foundation.