Define your target market and what you want from them.
Create marketing material
(brochures, flyer, postcards, website, etc.) that meets the desires of your target market and give them ways that they can really make a difference.
Show them how even a small donation can really make a difference.
Give them ways that they can get involved with the cause.
Keep a close relationship with those who become involved through newsletters and reports.
Show them what their efforts are accomplishing.
Discover how your target market can be connected with.
What their concerns are and how you can connect with them.