Tools and Techniques:
The following are links to threads within the Sketching Forum that contain information regarding sketching tools and techniques as they apply specifically to astronomical observations. These tutorials represent a great deal of work by their creators, and are representative of the admirable generosity that characterizes the Cloud Nights forum.
If you have an interest in sketching what you see at the eyepiece, check these threads first. Many common questions and problems are dealt with in considerable detail by these tutorials. Give these techniques a try, and then come share the results.

Is Your Image Too Big? (Archived)
Guidelines for determining, before you post, whether or not your image exceeds the CN posting rules.
Astronomy Sketch of the Day (Archived)
How well does a sketch represent an eyepiece view? by Jeremy Perez
Binocular mounts/mirrors for sketching
Books for Sketching (Archived)
Copyright, Your Sketches, And Historic Sketches (Archived) by Jeremy Perez
Deep Space Objects Sketching Tutorials and Tips (Archived)
Digital Tips, Tutorials, and creating Templates This appears to be unavailable...
Illuminating your sketch pad (Archived)
Lunar Sketching Tutorials (Archived)
Monthly Targets/Tutorials and Tips (Archived)
Observing log template by Southerner
Planet Sketching Tutorials and Tips This also appears to be unavailable...
Planet Templates (Archived)
Solar Sketching Tutorials and Tips (Archived)
Tips, Tricks, and Tutorials (Archived) by various contributors
Additional topics of interest and sketching resources:
Post your very first sketch over here!
Solar sketches by Erika Rix
Gallery of Sketching Contest Finalists