Creativity and context....

My favorite idea is the last one:

Meet one new person a day for a whole month. Talk to them, converse with them, get to know them. Talk with each of them frequently in subsequent days. You can easily do this online.

This one is also good:

Go on a physical-fitness campaign. Work out until you break a sweat at least one time every day. Seriously. Every single day.

And this is useful for parties:

Memorize something useless but ambitious, like pi to 100 digits, or the names of all the major chess openings, or all the U.S. vice presidents and the presidents they served.

Mostly, just break out of routine.