a) tell you how I know you
b) associate you with something - fandom, a song, a colour, a photo, etc.,
c) tell you something I like about you,
d) tell you a memory I have of you,
e) ask something I've always wanted to know about you,
f) tell you my favorite pic of yours,
g) in return, you must post this in your journal.

There is nothing else much to write done. Comment and I'll tell you the above.