Conceive a girl

Carol • Mother to 2 lovely kids Liam age 9 and Penelope (Penny) age 1 , also expecting baby number 3 due September 2016 ! 💙💗
Anyone got any tips for conceiving a daughter ? Myself and OH each have a son from previous relationships and would love a daughter ! 
​Any sex would be a blessing of course , but a girl would complete our family 
​Thanks in advance x