How to improve memory retention and recalling?

I want to improve my memory.I think i forget things that I am supposed to remember.Good memory is so effortless or involuntary activity,it happens by itself on its own.But it gets irritating when we forget simple things.We learn by making patterns,linking new information to something that is already there inside our brain.But I guess I forgot how to do it?
When,say for example,I understand some new concept,I know I have understood it.But when it comes to recalling that it seems to fade away.
How could I improve my memory? Any techniques?
How can I memorize things to remember them for long time?
How to improve recalling? No use of something inside our head that we cannot recall,and at appropriate times.
What techniques do you use to memorize things? It may seem that you don’t use any,but actually everyone does.Think again and let me know how you do it?
Do you listen to some some background music? I have heard it helps but I don’t feel so,does it help you and how it helps you? if it works for you.
Mnemonics could not be that good because I don’t think there are much things that it can be applied to.