Habakkuk 2:2 (NKJV)
The vision God has given to me is to teach God's Word and to help people learn how to put it into practice in their own life. This may sound like a very general thing because every minister should be able to teach God's Word. But some missionaries are more focused on evangelism, some missionaries are more focused on establishing churches, some missionaries are helping to meet the natural needs of people while also evangelizing or teaching people. Whatever area it may be the missionary needs to find a way to share their vision and make it clear so that anyone who is interested in helping the missionary can make the necessary connection and give their support.
Every missionary needs to stay with the work that God has called them to do and trust God to supply all of their needs. If missionaries get away from their primary calling and spend an undue amount of time raising support or getting involved in projects just trying to get people to support them it can be a negative thing because the missionary is getting away from the direction that God has given them. Our part is to make our vision plain and easy for others to hook up with and get involved with in the area of support. Whatever God has called a missionary to do is what the missionary needs to focus on and then find a way to make the vision clear to give people a way to become a partner with them in the work that God has called them to do.