"Tricks" .. "Guarantee"?? No, there is no such thing. Fertility clinics are one of the most successful businesses on this planet BECAUSE there are no 'special tricks' available to those who need assistance in conceiving.
Tracking her period will be very helpful. Why do I say this? Simple, tracking her period will make it easier to track her fertile days and the day she ovulates. The spermatozoon is "alive" in a female's vagina up to 4 days. Another thing. Try to be MOST active in her fertile days. The more you have sex within those days the more chances you have. :-)