You want a better memory?  Get a good night's sleep.  Don't be hungry, but don't be full either.  Don't have a headache.  Don't be stressing over something other than what you're trying to remember.

All that is the EASY stuff.  Now here's the tough one: actually care about what you are trying to remember.  If it's important enough to you, your brain will give you PTSD over it never mind just remember it.  Your brain loves to record novelty or trauma. So hopefully it's not something that important.  Just something emotionally significant will do.  Find a way to care enough and you'll remember.

But if you don't really, really care... repetition and testing yourself until you can't forget it at least in the short term.  That'll do it too, but it's really tedious.