1. You manually create a Project Summary Task
Wrong:
2. You "hard code" dates
Wrong:
3. You don't input the teams planned Duration on all tasks
Wrong:
4. Your tasks don't start with a verb
5. You assign Predecessors to Summary Tasks
Wrong:
6. You assign Resources to Summary Tasks
Wrong:
7. You never inspect the critical path tasks
8. You never search for (or eliminate) Resource Over-Allocations
9. You never Baseline your schedule
10. You never update your schedule to align with reality
For help with Microsoft Project, try
this link
You may find this book helpful: