I wanted to make blogging with markdown and textmate as easy as possible. I struggled to do this, though its very easy …

Textmate has a number of ways of doing key bindings. The thing I wanted to do was bind the menu item File | New From Template | Blogging | Blog Post Markdown. You cannot do this using System Preferences | Keyboard instead you have to do this in the bundle editor. Here you have to drill into the blogging bundles templates, and select the markdown template. Then assign a key binding to this (I chose ctrl meta option m).

In addition I modified the template text to include the line

Format: Markdown