I usually play a quiz before I post it many times to test things, but I'll usually play it one more time, just after midnight the day I posted it to give it one more final test (or if I post it early in the day, I play it shortly thereafter because I don't want to miss any errors).
That way, it also gets "advertised" once again in the news feed of activity on Sporcle among your friends. I NEVER ever ever challenge my friends to quizzes I make, because I researched and made them, and now I have an unfair advantage. Though, most of my friends who are crossword champions still beat me at many of my own quizzes, and everyone I know beats me at my own lyrics quizzes. My biggest pet peeve on Sporcle is if someone challenges me to a quiz they made; I immediately delete the challenge. For me, all my Sporcle friends are my real life friends with a smattering of Sporcle editors I've talked to or met in real-life.
If I want my friends to take my quizzes, I post them all on Facebook and Twitter, or I email them personally, but most of my close friends follow me or get alerts when I post quizzes.
Also, during the badge era, I've been making tons of quizzes every month to help me learn things I need to memorize for certain Sporcle badges, or I make quizzes in the categories and subscategories I need to play quizzes in to get other badges. And I'm also making these for several of my close friends who are also badge-obsessed.
I actually worry when I see someone who hasn't taken their own quiz, because I worry it hasn't been double-checked enough. Plus for me, just taking the 3,000 quizzes I've made got me a handful of badges :)
Chris/SproutCM