Snell’s Equity begins its commentary on trusts with the words ‘No one has yet succeeded in giving an entirely satisfactory definition of a trust (Snell Equity (30th edn, 2000) para 6-01). It proceeds, however, to say ‘perhaps the most satisfactory definition is that of Professors Sheridan and Keeton’:
‘A trust is the relationship which arises wherever a person (called the trustee) is compelled in equity to hold property, whether real or personal, and whether by legal or equitable title, for the benefit of some persons (of whom he may be one and who are termed beneficiaries) or for some object permitted by law, in such a way that the real benefit of the property accrues, not to the trustees, but to the beneficiaries or other objects of the trust.’ (Keeton and Sheridan The Law of Trusts (12th edn, 1993), p3).
The words ‘whether real or personal’ emphasise that trust property may be land or any other property. The words ‘whether by legal or equitable title’ emphasise that the trust property may be vested in the trustee for a legal or absolute estate or for an equitable interest, the trust property in the latter case being itself held under a trust.
Trusts can be classified as ‘express trusts’, ‘implied trusts’ and ‘constructive trusts’.
Jessel MR once observed that ‘it is a fallacy to suppose that every trustee has the same duties and liabilities’. Subject to this warning and to the question as to how far the usual duties of a trustee apply to a constructive trustee (This is an open question; see Lonrho v Fayed No 2)  1 W.L.R. 1 at 12, Millett J.), one must first consider the terms of the trust instrument (if any) creating the trust. It may be possible to find in such a particular trust instrument express additional duties for the trustees and (but only if the wording is clear) relaxations of the usual duties.
Snell distinguishes between the discharge of a trustee’s duties and the exercise of his discretions (and powers) in this way. In the former, he must ‘observe the utmost diligence’, observing the trust instrument and the rules of equity (unless the court otherwise orders) (Snell Equity (30th edn, 2000) para 11-02). In the latter, however, he must act honestly and with as much diligence as a prudent man of business would exercise in dealing with his own private affairs. This is still the basic test. However, in relation to specific activities, the Trustee Act 2000 (TA 2000) imposes on trustees an express statutory duty of care (TA 2000, s1. See 11.54. For further commentary on this Act see Reed and Wilson The Trustee Act 2000 – A Practical Guide (Jordans, 2001).
The primary entitlement of beneficiaries is to have the trust administered by the trustees or, failing that, by the court according to its terms and for the benefit of the beneficiaries. For instance, no element of bounty may be given by trustees out of the trust property to anyone except a beneficiary authorised by the trust instrument (if any) or otherwise entitled under the trust (if there is no such instrument).
It is a strict rule that a trustee cannot claim remuneration for his work unless he is clearly authorised to do so by the trust instrument, by TA 2000, s28 or s29, by all the possible beneficiaries (if they are of full age and capacity) or by the court (Snell, paras 11-87-11-92). Equally, without such authority, a trustee cannot employ at the expense of the trust his own firm to do work for the trust (Re Gates  Ch 913; Re Hill  Ch 623). For these reasons, it is usual to include in a trust instrument a ‘professional trustees’ charging clause’.
The position is quite different for actual expenditure incurred. A trustee is entitled to be indemnified out of the trust property against all costs, charges, expenses and liabilities properly incurred in administering the trust (Re Beddoe  1 Ch 547 at 558, CA; Holding and Management Limited v Property Holding and Investment Trust plc  1 W.L.R. 1313. It would seem that the statutory indemnity in the Trustee Act 2000, s 31 ought to be construed in the same way). The emphasis on the word ‘properly’ brings into play all the law on the trustees’ duties and powers.
Another aspect of this topic is the fact (previously mentioned) that courts of equity have always been prepared to assist trustees who are in doubt as to how they ought to act by giving them guidance, directions and protection. As Lord Simonds LC said in Chapman v Chapman:
‘It is the function of the court to execute a trust, to see that the trustees do their duty and to protect them if they do it, to direct them if they are in doubt, and, if they do wrong, to penalise them.’