depends what are you doing contemporary. decision are affected by numerous factor, like time, circumstances, family background, peer pressure, ambition, poverty, social status etc. specifically, in my case i look into the bigger picture of how the job i am going to select will serve my ambition along with my family and clan needs. similarly, am i of a little help to humanity or am i contributing something positive for the society, if the answer is yes, then i wont look back over the decision i made. as mentioned above those factors were kept in mind while choosing or making the decision. however, if things does not go as, i or you planned then the lesson is learnt of not going to make same mistakes again.
Start with the main topic and then break into sub categories
Ex:
Subject : cat meme
Sub: how did cat meme start
Sub: what are cat meme
Sub: how to make your own cat meme
Conclusion and thesis
I don't know who you will choose or their relationship with you, so here's a template to follow:
Dear [insert name],
Thank you for being kind this year. I remember the time when [insert a memory of when they were kind to someone]. That was very much appreciated. Being kind is very important in life, so keep it up!