That pretty much depends on the specific part of accounting you are handling. Generally there is a big ethical part, which perhaps outweighs the technical one. Being honest, on time, keeping secrets... are key.
Technical knowledge that could help you stand out are primarily:
1- Excel: advanced practical knowledge
2- Accounting standards: You don't have to know them all, but make sure that everything you do complies with the related standards and that you know these ones well.
3- General computer fluency: It's not about being a programmer, but being able to handle any accounting software is essential.
HTH