Create a system which is easy to use, where you can quickly store and access documents. Be selective about what you put in, be concise, update and weed out materials regularly. Divide your portfolio into sections - these can be themes, categories, or topics of interest. You can order things chronologically or divide by class/level. The structure will depend on your own teaching context and the purpose of your portfolio. Be prepared to be flexible and to add, change and delete regularly.