There are generally 3 types of tax shelter schemes involving registered charities:

• Buy low, donate high, where an individual buys property for say $300, then donates the property at a “fair market value” of $1,000, and receives a $1,000 receipt

• Gifting trust arrangements, where an individual donates say $300 cash to a charity, receives property with a purported fair market value of $700 from a trust which is also donated to charity, and receives a donation receipt of $1,000

• Leveraged cash donations, where an individual borrows $800 to donate to a charity and donates $200 out of pocket to the charity for a $1,000 donation receipt, then pays only $100 to repay the loan

see:

http://www.wfre.org/PDF/charity%20audit%20update%20-%20kitchener.pdf slide 33