Keep it easy
Lots of you have really got it together on the donation process, if so, you don't need to read this. But if you've yet to make the best of it, please... make it very easy for people to donate to your charity, especially direct from your website. If donors have to download a form, complete it and post it to you, it's going to put many people off. Here are a few ideas:
From your website: There are simple online methods that you can bolt onto your website, such as PayPal and Charity Checkout. Well worth the effort.
Online sites: Register with the likes of JustGiving, CAF, MyDonate, Charity Choice, etc and link direct to your own page on their websites.
Cheques, internet banking: Again, keep it simple and give them the information they need without lots of clicks.
Cash: Get donation envelopes and cash collection forms printed for events so you can claim Gift Aid… which will also help you capture e-mail and postal addresses.