It's hard to stay up-to-date on all the promotions run by Priority Club (the massive loyalty program behind omnipresent chains like Holiday Inn). The single best way is to follow Priority Club Insider, who does the Lord's work maintaining the ever-changing list of Priority Club promotions. Before you stay at any Priority Club property, you owe it to yourself to check out Priority Club Insider and make sure you're registered for all the relevant promotions.
That's where I learned about Priority Club's summer promotion, which allows you to earn double points or double miles starting with your second stay between June 1 and July 31, 2013 (starting with your first stay at Candlewood Suites and Staybridge Suites properties).
Register for the promotion now, before you forget.