Spike/Lilah
How Spike and Lilah Could Work by Sally
Female/Male Fatales in BTVS & ATS by Shadowkat

Lilah
Dossier by Jennifer-Oksana
Psychological Evaluation by Jennifer-Oksana
Writing Darkfic with Lilah by Jennifer-Oksana

Spike
Lovefool: Spike and Women by Sally
On Writing Spike by cousinjean
The Pre-Raphaelite Punk by Lesley
Spike: Basic Facts by Sally
Writing Spike: Love and Spike's Motives by Amberina

General Writing
Action Scenes: How to Write Them by Kaz
BDSM: Points to Think About by Kaz
Fluff: Making it Believable in Jossverse by Kaz
How to Write Good Fic by Amberina
Unconventional Pairings by Katriena Knights
Why Write Pre-Show Fanfic? by Kaz