For me, it was hunger. I would not eat enough, or I would eat foods that I considered to be 'safe'. Low fat everything, no treats, 'healthy' things. Although I still eat 'heathily' I have actively chosen to make sure I get nourished properly, and it helps. Firstly, it stops the empty stomach syndrome, helps you think properly. A starved mind doesn't see things clearly. Healthy oils for me was a huge step forward, and reading loads about nutrition. That way, when tempting foods come around, it is easier to say no, or even maybe, to have a little, without wanting to devour the lot! Because you are not starving.
Feeling sad, angry, or even bored can also be triggers. Finding a way to express ourselves is helpful (I took up art). For the anger, I'd go and dig the garden! It takes courage, determination, and a real WANT to recover. Once you start this, it does get a lot easier as each day passes. For me, it was like breaking a habit. Do not see it as loosing a freind, you will be getting rid of an enemy!
Another trigger can be wheat. In my younger days (before I learnt about nutrition) I would eat slices of bread to fill myself up. It would for a while, then I'd get really tired (energy slump) which would often result in binging. These days I eat bread very rarely. Coffee can also have this effect, it messes up your blood Sugar
levels. Simple carbohydrates can do this too, they are best avoided, or eaten with some protein to help them be digested slower.
For people that like to do right all the time, a good way of doing this is to do a few things 'wrong'. What is the worst that can happen? I've always been a laid-back sort of person, but used to suppress my emotions. This is not good. If you can tell others what you're thinking/feeling in a calm and caring way, it makes things so much easier.
Hope I've not bored anyone too much with all this waffling, I could go on all night (but I wont!).
Good luck and best wishes to all.