Types of gift
The same considerations apply to gifts to charities as gifts to individuals. In some cases a cash gift will be appropriate. But if a client wants to benefit a charity in a more significant way, it may be preferable to give a share of the residue. This can also ensure that the charity does not receive a disproportionately large (or small) share of the client’s estate if the value of the estate fluctuates sharply.
If your client is uncertain which charities to benefit, you can consider a discretionary gift, leaving the choice to their executors. This can also be useful if your client does not want the identity of their chosen charities to be known. In this situation a client can (and should) leave a letter setting out their wishes.