I set my recommenders deadlines a month before the actual deadline while giving them heads-up and questions 3 months in advance. I told them I want to apply earlier. I asked them if they are ready to commit and warned them that I will be ignoring all rules of politeness in reminding them of their commitment if they are late. I had very good relations with them, so saying this was not a problem despite their seniority in the global organisation.
Needless to say, I had to chase them up ferociously nevertheless. But I wasn't ashamed of reminding them multiple times - they committed, full stop.
Two recommenders sit with me in the same building but travel a lot while the third is based on another continent and travels a lot as well. After a couple of reminders to the former two, they started to tell me "I will do it tonight" before even saying "hi". I got my recs two weeks before the deadline but was really nervous. I used some tricks such as asking my former colleagues who can see whether the third recommender is in his office and is not on the phone to call him at that moment. I made about 5 or 6 reminder calls!!
In my situation those people had never written any MBA recommendations and they were afraid to start even though they were really keen to help. Make sure you educate them in advance and outline your expectations bluntly if your recommenders are as inexperienced as mine.
I decided not to buy any gifts before the admission to avoid creating a wrong impression. I did a lot for those guys both professionally and privately. I didn't feel obliged to buy any gifts and I guess they didn't expect me either. Not at this stage at least.
As HBSGrad said, it was (and still is) my damn future and I didn't want to let someone else screw it up!