diff --git a/WELCOME.md b/WELCOME.md
index f435a9c2..fa46f298 100644
--- a/WELCOME.md
+++ b/WELCOME.md
@@ -19,7 +19,7 @@ You can create a new document by clicking the button i
#### Switch to another document
-You can list all your local documents and switch from one to an other by clicking the button in the navigation bar.
+You can list all your local documents and switch from one to another by clicking the button in the navigation bar.
#### Rename a document
diff --git a/doc/theming.md b/doc/theming.md
index a8fd9f76..d5a4fe64 100644
--- a/doc/theming.md
+++ b/doc/theming.md
@@ -1,2 +1,35 @@
StackEdit theming guide
=======================
+
+In **StackEdit**, a theme is pretty much a CSS file that overrides the default look and feel.
+
+*Create your special theme very quickly by following these steps:*
+
+ 1. Fork **StackEdit** on [GitHub][1].
+
+ 2. In the `themes` folder, create a sub-folder containing your resources (CSS, images...).
+
+ > The CSS file should have the same name as the sub-folder.
+
+ > **Example:** `themes/cool-theme/cool-theme.css`
+
+ 3. Add an entry in `THEME_LIST` at the end of `config.js` with the folder name as a key and the name of your theme as a value.
+
+ > **Example:** `"cool-theme": "The coolest ever"`
+
+ 4. Run the application on your machine, go to `Settings -> Editor -> Theme` and select your theme. Check that everything is marvelous (don't forget to test the `viewer.html`).
+
+ 5. List your resource files in `cache.manifest`, commit, push, create a pull request and wait for publishing...
+
+That's it!
+
+### Please, keep in mind these simple rules
+
+ - Avoid using gradients, shadows and other effects as much as possible (for performance concern).
+ - Try to create something at least as nice as the default theme...
+
+
+> Written with [StackEdit](http://benweet.github.io/stackedit/).
+
+
+ [1]: https://github.com/benweet/stackedit
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