score:5
You are overlooking the most important word in your question, and that is 'gift'. A gift is something that is freely given - the giver chooses whether or not to give, and the receiver can only choose whether or not to accept it - if it is given. If the receiver can compel the giver in any way, or tries to earn it, then it isn't a gift. It's long been part of Christian theology that Tongues and rather supernatural abilities are 'gifts' in that sense. Check out 1 Corinthians 12, where this is made explicit. Also check out 1 Corinthians 13, which is an explanation of something better and more important than spiritual gifts - Love. It's not accidental that those chapters are next to each other.
General advice as far as I know is that if you earnestly desire a specific gift, keep praying for it. But be aware, as with all other prayers, God may not grant you what you are asking. He may have a better, alternative plan for you.
The exceptions to this are the Pentecostal traditions where speaking in tongues is a sure and necessary sign of being a true believer. In that case if you don't have that gift, consult with a Pastor.