Great direct mail advice although I can't agree with \#25 and \#34.

Mistake 25: writing a package and then surrendering it to an artist.  Lean over the artist’s shoulder all the way.  It’s your package.  And don’t just give verbal instructions.  Make a rough pencil layout.  The artist’s responsibility is to enhance your concept to make the package visually exciting – but only within the framework of your vision for the package.

This makes it seem like artists, left on their own, will always detract from effectiveness. The best work we see is when artist and writers collaborate.

Mistake 34: failing to understand that the only reason you write to $10 and under donors is to motivate them to step up to a higher level.  If you let them stay at $10, your fundraising costs may be embarrassingly high.  So learn all you can about upgrading techniques.

We've found at Masterworks that donors who give you less than around $20 on a first gift never give enough subsequently to make up for it. Perhaps in other areas of direct marketing it's different, but with our clients it is better to stop mailing $10 donors than try to upgrade.