1. Go to the design pattern page and check if the design pattern you're thinking of is already there.
2. Assuming it isn't click “Edit this Page” or “Edit” by the list of patterns.
3. Find the right place to insert your new pattern (*hint* they are sorted alphabetically).
4. Add a new link for your pattern, see quick_syntax for how to create a link.
5. Save your changes.
6. Follow the link and click on “Create this Page”.
7. Fill out the new page and you're done!

These are some high level guidelines to help guide a new contributor. The goal is to have documents share a common form so that it is easier for readers and writers to do what they came to do. When discussing a design pattern you should keep six different headings in mind:

1. An introduction
2. Lengthier description
3. An example
4. Discussion of advantages,
5. and disadvantages
6. References to related patterns and documents

This section should be short and to the point. It might be titled “Introduction” or “Motivation”. The goal of this section is to sell the reader on the pattern. After reading the introduction it should be clear whether I need to learn more about the pattern or not; thus a good way to start is to introduce a problem which the pattern will solve.

At this point you've done your salesman bit so now you've got to enter into a longer discussion on the finer points of the pattern. This section's length can vary. If you're going to include a code example or an UML diagram then it makes sense to keep the description short. On the other hand, without additional tools you'll need to describe what the pattern is and how it works here.

This is one of the most important sections. Try to create a clear code example or, even better, an UML diagram to represent the pattern. By this point the reader should know what's going on (thanks to your clear and helpful description) and just needs this section to verify his intuitions.

Here you'll write one or two sections looking at the advantages and drawbacks associated with adopting the pattern. The advantages will hopefully be clear from reading the motivation and description sections, but you may have a few surprises. The section on drawbacks is especially important since it may not be clear to the reader that adopting a pattern has any cost.

Title this section “See Also”, “References”, or “Related”. It should be a list of resources that the reader might find interesting after reading about the pattern.