One of the most important things is finishing well.  I suggest a group feedback and prayer time. 

Get all the team members to gather in a circle. Only invite those who are on team and have been part of the mission experience (so people can share openly about the week).  Leading this is not something to delegate.  Start getting feedback from those who are newest and mission and have had significant spiritual growth experiences.  Then work up to the more experienced members, finishing with the team leaders.

Don't worry if all this takes a while.  It's terrific for people to go home, not with just their own positive experience, but having heard the experience of all the other team members.

Try to ensure that every team member tell of their praise point experience of:
growing in Christ through the mission experience
seeing others grow in Christ.

Then break into small groups to pray for those around.

Prepare the team members for going back to work tomorrow.  Warn them:

• They will feel both an enormous sense of spiritual anticlimax.
• They will be a little annoyed with some of their other Christian friends who it will feel to them are ‘jogging in molasses’ or ‘running in slow motion.’ Let them know that it’s them who have changed not their Christian friends.