Any is fine, u don't need to do anything special to conceive, u just need to have sex at the right time. People who say they conceived by doing something particular, having sex a certain way, using a special lube, sleeping after sex, using soft cups etc etc don't actually know whether they would have conceived that month without doing those things. It certainly can't hurt to do everything they say like missionary, laying down for ages after etc but really if u haven't been TTC for ages I wud just go with the flow and have sex how u want to, u will enjoy it more, when sex becomes a chore that's when u stop doing it so much and then ur chances fall. Good luck to u all xx