You can offer exclusive or early-access content, behind-the-scenes insights into your work, small extras, or opportunities to connect. The most important thing is not an extensive rewards catalogue, but that your community feels this: their backing makes your work possible – and brings them closer to it.
It is also worth knowing that the best rewards are often part of the work you already do – the very work your community loves you for. You don't need to reinvent the wheel. Simply ask yourself: Which things do I already do or have that could become a reward?