Okay, we're getting to the point where most actions have been defined, but the verbals aren't yet complete. I've got Jennifer working on disciple verbals using these guidelines, and so far they're turning out pretty well. So, when you're working on verbals, keep the following things in mind.
Length. Verbals should be brief, but not too brief. Seven to ten syllables is a good minimum.
English. I know I'll be called a hypocrite for this, but let's keep verbals in the English language for the time being. At a later date, we may experiment with other languages, but I'd rather keep things simpler for casters. And I hate the idea of grossly mispronounced verbals.
Evocative. The verbal should describe what is happening, both visually and to the recipient. This helps everyone to better envision it in play, and helps the recipient act out an appropriate response.
Distinctive. Variety is the spice of life even in the fantasy world. Now, I have the utmost respect for Solar, but I've always felt that the whole, "I call upon the X to Y," formula is a bit overused.
If you can think of any more guidelines to make outstanding verbals, post them in the comments below and I'll update the main post.