1. prepare your CV/resume with the most updated information
2. write a rough draft of your personal statement
3. collect unofficial transcripts from your institution
4. make an interfolio account/pay for more than 1 year subscription
5. give all of this paperwork to your prof and give him/her a hard deadline that you need it by (make sure deadline is sensible like 1-2 months out)
6. send out formal request from interfolio
7. check in on them and make sure they received the request
8. bug him/her for every week they are late on turning in for deadline
9. send updates/thank yous during your app cycle in case they need to update a letter, change the date or call your schools
10. good luck