Here's a quick list of some of the options that should be considered for logo artwork. Now, this doesn't get into symbology or anything like that, but, it's a good list of stylizations and thoughts to explore when embellishing a logo concept.

Main logo types:
Text treatment
Symbol-only
Combination logo (text and symbol)

Text ideas:
Initials
Combining fonts
Integrating letters

Icon ideas:
Representational
Abstract
Cartoon

Icon placement:
Centered above text
To the left of text
To the right of text
Integrated with text
Behind text
Askew

Shape:
Round
Square
Oval
Swoosh
Rectangle
Hexagon

Stylization:
Clean
Brushstroke
Square edged
Round edged
Elegant
Calligraphy
Swash
Dashes
Dots
Outlined
3-D
Funky
Overlap
Animal symbolism
Broken Shapes
Reversed out
One shape inside another
Seal
Fine lines
Repetition
Intersection
Shadow