reading my last two posts above, you should be able to conclude that I do not have the perfect solution for DOnationware either. I am struggling myself, being a developer AND a user. But here is my third and last post for today (I think): my two cents for mouser/this community.
1. Make the registration rules as SIMPLE as can be, as few options, etc. KISS = Keep It Simple Stupid
2. In case of freeware, small programs, low risk of loss if income: don't ask for any donation before the user is a REGULAR user (6 months or so)
3. The website: the more professional the website looks (I know, mine is not perfect either, updates planned) the higher the chance people will be willing to give their email address and to donate.
The third option may be new to this discussion. It is not my intention to bash at this website, it is meant as a genaral statement. For this website I feel the software could be presented a bit better, a more solid standard (per program three screenshots, etc)
ALl the best to DonationWare, I will keep reading this topic and the site!