If you have status on one airline or hotel chain, you may be able to have another airline or hotel chain match it. So, for example, if you are Gold on American Airlines and are a nobody on AirBerlin, you can request a status match on AB before your next flight and receive the privileges that your new (temporary) AB status grants.
This post from Dan’s Deals is a very useful summary.
It isn’t easy to keep your SPG (Starwood Preferred Guest) points from expiring. The standard ways to get some activity in your account is to stay at a Sheraton hotel, or to make a purchase with your SPG credit card.
Another way is to check your Dashboard and see if the Uber promo is available on your account…it gives you one point per dollar spent on Uber. So, a short ride is enough to give some activity in your Starwood account, and presumably extend the life of your Starpoints.
A fourth method to get some points, if your are targeted (I was not), is described in this blog post: