There are some niyama or rules for Navratri.

1. Maintain neatness in the puja place.
2. Avoid eating non-vegetarian food during Navratri vrat.
3. Make a timetable for puja and follow that.
4. Avoid entertainment and other recreational activities as much as possible.
5. Avoid maithuna or sexual activities during Navratri.
6. Charity is the main aspect of Navratri. Do charity and donation as much as you can.
7. Food charity is the main aspect of this puja. A kanya or suhasini should be fed.
8. Spend as much as time in Devi Prarthana as possible.