Find promotions to create activity on your account. Credit cards are the easy way. Otherwise I transfer points (e.g., to Hilton, Hyatt), or just create activity (AAdvantage email promotions, TD Ameritrade account fund). For SPG I am not sure what expiration requirements are, but perhaps you can transfer from AMEX to SPG to count as activity? I'm sure its been discussed on the SPG forum if you do a quick search. One tip for managing your accounts is to use an aggregator, like Award Wallet.