One must use a Red Sandalwood Counting Rosary for the chanting and light a Diya in front of Hanuman.
Other than that, there are no more rules or requirements prescribed in order to chant this beneficial all purposes Lord Hanuman Moola Mantra.
One can chant as much as they want. However, if one chants 11 rosaries daily then one will achieve favourable result more quickly.
Mantra : || ॐ ह्रां ह्रीं ह्रूं ह्रैं ह्रौं ह्रः ॐ ||
|| om hraang hreeng hrung hraing hraung hraha om ||