As a time saver, I've cut and pasted the entry. Here:
Steps
-Apply some darker foundation.
-Use brown eyeliner to make the wrinkles.
-Wear something from your grandma's wardrobe, preferably a dress.
-Match it with old-fashioned shoes
-Tease your hair and powder it, so that it looks white or grey.
-Wear fake, extravagant jewellery(it's better if it's gold).
Tips
-To appear more believable, fake an old woman's voice and speak like old people do.
-You can also carry a bag or a walking stick.
-Say stuff like "Back in my day" or "Before the war..."
"OUTRAGEOUS LIES! A BROAD, DEMEANING CHARACTERIZATION! I'M OUTRAGED!"
Another big thanks to the combined wisdom of millions/the Wiki Age. The world is flat y'all! Happy Halloween.