What works for me;
Blank mind, STOP thinking (main problem most off the time) and say whatever comes up first.
If nothing comes up, start with 'did you know that ....' or 'look at .... how weird' or 'Yesterday/today I did ....' or 'BUYAAAA' while throwing your arms in the air and THEN saying whatever comes to mind (after you both stop laughing
).
Point being;
Doesn't really matter what you say.