The trustees' main duties are as follows.
To invest the trust fund
To act impartially, if providing different benefits to each beneficiary
Trustees may delegate their powers of investment and management to someone else
To obtain and consider proper advice before exercising powers of investment
To secure the trust property
To keep records of any decisions and actions, as they may need to prove they are managing the trust fund properly
To not use the trust to benefit themselves. If the trustee is also a beneficiary, then they must not use their powers as a trustee to gain any benefits over the other beneficiaries.
You can find more information about the role of trustee in our guide to being a trustee (PDF).