If you are a UK taxpayer, you can substantially increase the value of your giving and donations by signing a Gift Aid form.
Under Gift Aid, the Government will refund to the Parish the tax you have already paid on the donations to make to it. At a basic income tax rate of 20%, for every £10 you donate, the Parish will receive a further £2.50 from HMRC! And it doesn't cost you a penny extra.
A short brochure setting out fuller details, and including an application form, can be downloaded here.