Sometimes, when I want to feel nostalgic, I'll play music that I listened to heavily during a past period of my life. Music is second only to smell in that it can transport you to another time with a single twinge of the sense. And it's much more convenient to recreate on demand than odours.
Other times I might read through an old year worth of journal entries to reminisce. It's amazing what kind of extra memories are conjured simply by reading through thoughts I wrote at the time. I feel plugged in to that era.
On days I'm feeling really narcissistic I'll do both. The year's top singles while reading the year's posted experiences. It's like my mind is right there back in 2011 or 2007.
Sometimes I'll listen to the top songs from one year while reading the journal entries from a completely different year. That's an uncanny mental sensation. I can feel parts of my brain distorting in jelly-like ripples as it tries to chronologically orient itself while being thrashed by waves of nostalgia.
Sometimes I like to turn the hairdryer at my armpit and hold it there. There's a point right before the skin burns where the nerves tingle in a way I've never felt anywhere else on my body. I don't know if it's pleasure or pain, but something makes me keep doing it.