The campaign has published two reports with think-tank NFP Synergy, outlining the opportunities available to charities in these two schemes.
Share giving, whereby a donor gives shares to charity and is then able to claim tax relief on the market value of the shares, was worth £150m in the 2001/02 financial year.
Share Giving - Fundraising's Road to Riches? advises charities to begin to take advantage of this potential goldmine by targeting share giving at high-value donors and promoting the method as part of a complete service for supporters.
"The really exciting prospect is that when charities do start to comprehensively build share giving into their fundraising mix, we could see £500m or even £1bn raised each year within a decade," said Joe Saxton, director of NFP Synergy.
The report also suggests that charities should promote share giving little and often and should make sure that promotions are timely, for example when there are 'windfall' share hand-outs.
"Share giving is clearly a great way to attract high-level donations and, if you're not already promoting it to donors more widely, I would urge you to get started," said Giving Campaign director Amanda Delew.
The second report, You Can Take a Gift Aid Horse to Water..., found that charities are still not making the most of Gift Aid, despite 93 per cent admitting that the scheme has made it easier to reclaim tax.
The report recommends charities appoint a 'tsar' to champion the scheme within their organisation, to brief staff and volunteers on the importance of tax-efficient giving and build Gift Aid targets into their annual reports.
It also says charities should target donors who persistently fail to sign up to the scheme.