B-schools strongly advise against it. Reading
this guy's website (click link) made me wonder how common the practice is in reality, though.
While all of my recommenders (5, I split between schools) fit the "too busy" category, and I only interact with one regularly, they all got it in on time. I assembled a packet of info for each consisting of:
* Some of my app material for them (resume, 1 sample essay (HBS #1 'accomplishments' is a great one to use))
* Since my company has a 360* feedback system (and after checking with my management and HR on policy), I copied good feedback (and attributed it) from performance cycles. I edited that from 15 pages down to 6 and kept only the best quotes from people who'd worked with me. The idea was to give the recommenders a 'greatest hits' of feedback to see if any situations resonated with their impressions of me or sparked memories of similar behaviors. (Many of them were also quoted in there, so jogging the memory there was a bit easier!)
* I liked the
Universal Recommendation Form so I included it, then for each recommend tried to jot notes about projects or interactions that I wanted them to remember.
* Finally, I included a cover letter/index and a summary of the strengths of each school I wanted a rec for and the reasons I wanted to go there.
I met with them each individually and asked formally for their help, and when they asked when it was due I gave them about a month before the actual deadline, as that was my target. (Given our company and our workloads, I knew that would be highly unlikely, so I padded a bit)
I did get some great feedback from my recs about the work I'd put into the packets. Taking it seriously shows them how serious you are about it, and the best way to help your recs present you - especially those that are incredibly busy and can barely remember that project from 3 months ago - is to jog their memory.
Anyhoo, good luck. It's an ethics thing, frankly, and I wouldn't do it, but apparently plenty of folks write their own.