I am sure there are times, you would have forgotten things and I did too. When I was checking online for a solution on this people where area asking us to write notes about what to be done and use it to remind ourself. An important step is you have to write it and keep it in a place which you remember and you also need to remember taking this note and going through the list which is as equal as remembering things.
But I wanted to solve it in easy way. So, I started connecting things in my activity which makes me to remember only one key factor in the process.
For example, You are asked to bring documents to the office, the main activity in this process will be your journey from home to the office which you will do eventually. So, tag your documents to your car/bike keys. So next day it will be easy for you to take the documents to the office.
It is that simple. Find important thing in your activity and connect things which you want to remember. Happy Remembering!