The most basic place for gratitude is in the very fact that we exist at all.
This gets weird when you think about it too much.
The only reason we can even think about being grateful for anything at all is because we exist. Whatever it is at the mouth of this river of consciousness, this awareness, gives us that, and this is the first place for gratitude.
I often think that no matter what is happening around me, at least I am here to experience it. This is especially noticeable when death is near me, either someone I love has passed away or I am helping someone walk through the death of someone they love. Those moments suck, but at least we are there to witness them at all.
The alternative to all of this is nothing.
I often hear people say they would rather experience nothing than what they are experiencing at the moment, but there is even an expression of awareness in this statement. Sure, nothingness seems nice sometimes, but when we say that we are, in some way, envisioning ourselves experiencing it. We are existing in nothingness, which makes almost no sense at all.