I threw a Spy Party for my 5yo and couldn't find any party cups (or anything!) with spy stuff on it. So I made my own! They were a real hit :-)
I also made cupcake flags which I will prob post here sometime.
One A4 sheet will make two cups (as shown in the picture) but you could fiddle with sizes to make bigger or smaller cups.
Once you get your design made these are super easy and take about half an hour to make 20 or so.
Use a program like publisher to create the design you want. (or just use a pre-printed page that you like)
Mine says "Happy Birthday Special Agent Sam" and I used clipart footprints.
Make sure the design goes all the way up to the long edges on the paper and has some sort of design or pattern all the way to the centre of the page. (otherwise the design gets lost and you end up with a mostly white cup)
Note that one sheet will make two cups so just create an image on half the page and then copy, paste, rotate to make the other side too.
Cut the sheet in half longways.
Using a small cup (with straight sides) wrap the paper (one of the half sheets) around and secure with a piece of sticky tape (or double sided tape if you're feeling fancy).
This may take a couple of goes to get right.
Note that you will need to leave enough 'hem' at the bottom to fold over and completely cover the base of the cup.
Go around the base and fold the 'hem' over to make the base of the cup. Secure it with one piece of sticky tape.
Be careful not to stick the paper to the cup itself or it won't come off easily.
Press the bottom into the palm of your hand so it is nice and flat and even and sits up properly when you stand it up.
This shows the base all taped up
Slide the paper off the cup....
...and fill with something yummy!
My son just said - "You can have popcorn or anything that's not runny!" - that's pretty good advice :-)