WHAT YOU SHOULD DO BEFORE APPROACHING SOMEONE FOR LOR?
Write a list of potential referees, preferably they should be in the course or subject area you are interested in you are interested in. You should have done this way ahead of time. I did mine almost a year ahead of my proposed application but while I am not necessarily recommending the same, I would recommend about four months. This will give you enough time to rank and inquire more about your referees. You should use this to find out who is experienced in writing such letters and who is not. Inquire about their favourite relaxation centre and when you are most likely to meet them. Pay courtesy visits or give cards during festive period so they would always have you in their subconscious
Read and have a lot of sample L.O.Rs. A simple search on Google images would bring a legion of samples you can easily go through. However, I have included real samples in this book. Make copies of your CV. This is crucial. It allows your referee to have an idea on what to write vis a vis awards, leadership positions e.t.c In addition, make a draft of your L.O.R, one your referee can work on. It is common for your referees to be too busy to start and many of them would require a sample and/or a draft. The draft acts as a sketch for them to build up on while the samples act as a guide to tailor the letter after.
I have included two documents adapted from the college counselling source book, 7th edition, 2012 the College Board. The first is a survey you have to fill yourself, the next is a questionnaire you can have someone closer to you like a junior colleague of your intending referee fill. These documents may be useful to your referees along with other earlier listed documents.