if it is going to a big one or just a simple kind of occasion. in this way, it would be very easy for you to come up with the things that you would be needing for the whole even including the decorations, foods, games, and even sounds.
if you are ready, you can take down all the things in your mind and finalize it afterward. you can ask your friends for any suggestions as well and they can also choose and select the kind of things that can be used for the party.
if your list is already complete. you can now review all the things that you have written there. 