The National Council for Voluntary Organisations and the Charities Aid Foundation have given the advice as they announce early findings from their annual survey on giving.
James Georgalakis, PRO at the NCVO said: 'Many charities are taking advantage of tax efficient methods but more needs to be done to educate people on how to donate in a planned and efficient way.
'Giving a regular sum each month or taking advantage of tax credits helps charities to plan their finances,' he added.
Early findings from the survey, for release next summer, have found that while donations remain on a par with last year, they are not improving.
NCVO chief executive Stuart Ethrington added: 'As funding from the National Lottery continues to fall and stock markets falter, all UK charities must prepare for an uncertain financial future.'