If you are going to make your own costume, say mens pirate costume,you are definitely going to have to find your own Halloween costume accessories to go with what you envision in your mind. Once you know what you want to make, or after your child has made a request, you can probably figure out what accessories you are going to need for that costume.
If you are not totally sure, look for that same costume somewhere else to see what others include, or just browse through a selection of Halloween costume accessories to see what catches your eye. You will come up with all the right pieces this way.
You may find that some Halloween costume accessories that you buy can be used for other ideas or even other events. Some things can be saved for when your children want to play dress up. Whatever the case, you should make sure you take a little time to clean things up if you are going to save them for another time.
You can wash the costume (hand-washing is usually a good idea) if it is made with fabric, and then you can wash any accessories you have used with a mild detergent and then let air dry. Once you have done that, you can put them away for later.