Jonathon Grapsas posted this video about some last minute tips that can have an impact on how well your year end appeal will do. But you might find that some of his tips will work for any mailing you work on during the year. Take a look:
Creatively, there tend to be two approaches to year end appeals that you can consider. You can either use the holiday season or Christmas thematically to tie in the importance of a gift – especially as the donors start to madly run around buying gifts for all of their loved ones, you are sending a friendly reminder to consider your cause as well. Secondly, you can use another traditional device – the thermometer. The message revolves around the idea that it is year end, and as much as your donors have rolled up their sleeves, you are not… quite… there… Again, reminding them of the things you’ve been able to accomplish to date and the few things you are hoping to do before the year runs out and how important that last gift will be.
One last thing: try not to mail your appeal in a white #10 (because everyone else will be!). If you have to use a #10, consider using coloured stock, or a bright colour on the front and back.
Good luck with your year end appeals.
EDIT: also found this great post from Pamela Grow for 5 more down and dirty tips you can use on your year end appeal. Thanks Pamela!
And this: Top 10 Ways to Screw up Your Year-End Fundraising Campaign by Gail Perry.