1. Ensure your fiscal sponsor is fully aware of its responsibilities for managing the project
2. Do a decent risk assessment that focuses on risks of your proposed operating model
3. Find out how much it’s going to cost you
4. Check if your funder allows it
5. Communicate clearly with your funder about how the arrangement is going to work, and let them know if things go wrong
TL;DR
In advance, it is important to agree with your fiscal sponsor what the division of roles and responsibilities within the project will be.
A good risk assessment focusing on the risks of your proposed operating model is essential.
Costs associated with acting as a fiscal sponsor and can vary a lot. Remember to find these out and factor them into your project budget.
As grant recipient, it will be your responsibility to make sure that your funder is fully aware of your intended method of receiving and spending money.
Communication is key. Make your methods of working clear so that the funder knows what to expect.