I'm not sure if there's any easy way that doesn't cost much. If you do draft a specific license for this person, how in the world would you enforce it or treat any violations? Wouldn't that entail legal fees that may just be beyond your financial limits?
In my opinion, for individuals who do not have the financial means or the time to file and track lawsuits, the source for any program should either be released using GPL or some other free license like the BSD style license (that allows proprietary modifications to be made without having to release the modified source) so that anybody can freely use and modify it. Although plain trust may work in many cases, there's no guarantee that it will always work. One bit torrent file and tracker or an ftp server for a few hours is all it takes to let any piece of information run uncontrollably in the big, wild cyberworld.
The other option is to sell the source for an agreed sum and forget about what the other person might possibly do with it.
As for shareware vs donationware vs crippleware, I don't think any of them are good options to sell software, although shareware seems to be the best of the lot.
Shareware is good to get a little money from your effort and also possibly build confidence and reputation in your users about how good your other commercial products might be.
Donationware is pretty much useless for making any amount of money - if 10000 users download the app, hardly 3 or 4 would pay anything for it (not even the price of a cup of coffee). The writer of donationware is rarely rewarded adequately for the effort. It does help in building a reputation though, if that matters. People do like the idea of supporting donationware, but statistics often indicate that they rarely put it to practice.
Crippleware is a strict no-no - almost all users hate crippleware for various reasons (including the one stated in another response here). Crippleware will force some people to not even try it (in cases where some might probably have tried a full featured shareware and paid for it later). While people will blindly buy a Photoshop or a Final Cut for several hundred dollars just because others say these are good apps, they will refuse to pay for something that was, in their opinion, supposed to be full featured software but in actuality makes them feel that the author does not trust them - dunno if this made much sense.
For individuals, killer app and/or great reputation are the main keys to selling software (ok, there are other factors too - if only life were this simple!).
Coming back to your question - as you've seen, I really don't have any good answers.
If you have the financial and legal prowess, draft a proper license and agreement and then release the code to that person. Otherwise be happy to release it to the entire world using one of the free licenses.