Before going on a fieldtrip know the children in your care. Is the activity appropriate for your group? Do you have children who need extra support? Will you have lunch at the fieldtrip site?
Make sure all circumstances are beneficial for the fieldtrip to be successful and increase the number of staff to create a smaller staff / child ratio. If you have never been to the fieldtrip site before it will be a good idea to have one person scout out the site first and report possible safety hazards and concerns.
Review safety practices with the children before you take them out of their usual environment.
Teach children safety skills (e.g. never talk to strangers, never approach strange animals, street safety rules, etc.)
If a child has wandered off / has become lost take these steps at once:
Analyze and debrief the incident with staff and the children. Use the teachable moment with the children and develop appropriate recommendations. Implement necessary changes to your fieldtrip safety plan to avoid the possibility of a reoccurrence.