1) Go where there is a need. It has always been my ambition to preach the gospel where Christ was not known. -Romans 15:20
2) Go where you can make disciples (invest in relationships and disciple them into disciplers). We loved you so much that we shared with you not only God's Good News but our own lives, too. -1 Thessalonians 2:8
3) Go where there is long-term follow up in place.
4) Go with people and/or an organization that you know.
5) Go where you want to go.
6) Go wisely. Ask you spiritual leaders for help! They will often have resources and connections that will help you tremendously. What spiritual leader would not want to hear: "Thank you for investing in me! I want to GO and make disciples among the unreached. Can you help me through the process?"
Plans go wrong for lack of advice; many advisers bring success. -Proverbs 15:22
Therefore, go and make disciples of all the nations...