A fruitful missionary is one who has been sent (commissioned) from a home church and who continues to be supported prayerfully, financially, spiritually, and emotionally whilst they serve in the field.
Not everyone is called to go, but all believers are to partake in the Great Commission of making disciples of all people groups (Matt. 28:19). Those who go must be sent into the harvest field (Matt. 9:37-38). Jesus is sending his workers into the field, but he is sending them through his body, the church.
So, how can Christians (and churches) send well?