The most important synchronicities are the ones we never notice. When you see a coincidence, infer meaning, and attribute that to some higher power or system of reality, it is because God is beating a message into you because you are a moron. God is fluid and subtle, no one can prove God's existence because that is the way God wants it. If you are in touch with God at all, you will never see a mircale, ever. They will simply happen all around you, but your life and your focus will already be beyond them.This is a bit rougher than what I would say, and I can't say with certainty what causes synchronicities in the first place, but I do think it is better to look past them.
When you look into a microwave oven, you see the food, but in front of the food is a metal mesh. The holes in the metal mesh allow visible light to pass through, but microwaves have a much longer wavelength. They are effectively too big to fit throught the holes. The mesh is placed the to keep the microwaves inside the oven, and so it is in a certain sense a sign of the existence of the waves themselves. But if you just look and see the mesh, you have missed the whole point of the oven. Look at the food and see what effect the microwaves have on it.
Do not look for syncronicities or coincidences. At worst you are stupid for seeing something pointless as significant, at best you are stupid for missing the point. (but then those are really the same, aren't they?)
Instead look at people. If the microwaves are present, the food will cook. So it is with God.
Buddha taught not to follow a teacher who claimed supernatural powers. Even if they were true, they did not help with enlightenment, more likely they were distractions.
I think it's fine to notice syncronicities, but I think it is wrong to base your life on them.