Now I am going to give you a practical approach to reach out and receive the gift for yourself. This is mostly based off of my own experience, but is grounded in the truth we have thus far looked at. This is a relational gift, so everyone approaches it somewhat differently and everyone practices it somewhat differently. There is no way to give step-by-step instructions, so what I will do is give some general guidance to help put you into a place to receive.
First and foremost, you must be a disciple of Jesus in order to receive this gift. Ephesians 1.13 says, "...In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit." Jesus--who is God--came to the earth and died on the cross paying the penalty for your sins (1 Cor 15.3). Then He rose from the grave and now provides us new life in Him (1 John 5.12, Rom 6.5-10). And with that new life, comes our "helper." He is known by many names in the scriptures, but is most commonly known to us as "Holy Spirit." It is only by Him that we are able to exercise any spiritual gifts. If you have Holy Spirit living in you, you are ready to go!
First, you need to find a suitable location. This is important. You might assume that a quiet, secluded corner a park or being home alone in a quiet room would be best, but neither is probably best when first starting out. What you need, is a place where other people can not hear you (you do not want to be self-conscious) and where you can occupy your ears. I would suggest that your car might be the best place to start out.
The biggest struggle you have at the beginning is separating your mind from what your body doing, so the best thing you can do it stop your ears from hearing what is coming out of your mouth. One great way to do this is by sitting in your car with some good classical or worship music turned up loud. Or you could find a secluded area and put on headphones with music. Another good location could be a loud worship service where you could sit in the back and speak without others noticing. The point is to find an area where you will not be self-conscious, and where your ears will be occupied, so your mouth is free.
When you have found a suitable location and are ready to go, you might want to start by praying (in your regular language) or singing a song of worship, just to get you focused. When you are ready to begin, ask Holy Spirit to come and fill you and give you the gift of tongues. Then take a step of faith and start making sounds. Everyone starts off with different sounds, there is no correct formula. Just start speaking what to you will probably sound like gibberish and let Him take over. It probably will not feel very spiritual at first, for me it took a few days, but it is an exercise in faith and you can trust that inside you are communing with Holy Spirit. As you continue to reach out, take moments to ask Holy Spirit for more and thank Him for what you trust He is doing in you.
If you honestly reach out in faith to Holy Spirit, the gift will come. It took me a few days before it felt "spiritual" to my consciousness, but there came a wonderful point when I realized I was no longer just making sounds, my mouth was actually forming words and it felt like they were bursting out of my belly! It was absolutely the most incredible spiritual experience of my life.
You can receive this gift, you just need to reach out. But let me warn you, it will change your life.