Use make-up so you look like you have some good bruising on one eye. Cut a few letter "P"s and use fabric glue to temporarily attach all over your shirt. Voila: BLACK-EYED "P"s!
Go as a marathoner!
You can layer up according to whatever weather you encounter, but the look you want is:
- T-shirt of some sort (short or long sleeves)
- Shorts or leggings
- Running shoes
In addition, the flair you add to look authentic:
- Racing bib: Take a piece of paper and use a marker (or print out) big numbers. You can even look online for some templates that make it look really real (like How to print your #Anywhere5K race bib). You will want to take a couple of safety pins with you so you can pin the bib to the front of your shirt. THIS IS KEY!!!
- Finisher's medal: Just cut out a circle (about 3 inches wide) out of cardboard and cover it with aluminum foil. Then stick a piece of round paper on one side and write "FINISHER" on it. Poke a hole on the top, and run a ribbon through it. If you have any leftover ribbon from Christmas wrapping that will work fine.
Now... like I said, you can adjust this to ANY weather. If it's really cold, wear a long-sleeve shirt. Layer extra layers underneath. Same with bottoms. Wear leggings, tights, etc. under your shorts. If you have a pair of gym shorts (that you might wear as pajamas in your hotel room) this is perfect.
If you want to add extra touches, wear a ball cap or visor, and maybe hang a towel around your neck, and carry a bottle of water in one hand.