Although there is already a trick to remembering the difference between the Cosine and Sine functions, like the y-intercepts:
Cos = 1
Sin = 0
But I find remembering with this following trick easier:
Let's flip things around for Cos...
This may sound childish but if you rotate the whole cartesian plane 90° towards the right, you will see somewhat of a "C"!
And for the Sine well...
And like Miss McGoldrick says, for the Sine function, well, sssssine for sssssnake!