**WARNING: LONG, but hopefully worth it. A discussion of things NOT to do.**
That's OK, Brandon. I specialize in SPaG (spelling, punctuation and grammar) too, and I throw Capitalization and formatting inconsistencies into the mix too. That's all part of proofreading. If you're good at that, you can be a proofreader.
I noticed a few things over the years that make a critique more valuable. For instance:
- Eliminate "crutch words". These include
“and,” “well,” “but,” “so” and “you know” -- and also mere sounds like “ah,” “um” and “er.” Sometimes they include words such as
“literally”, “actually” and
“basically”. Whatever form they take, crutch words are typically overused and meaningless.
For example, what good do these crutch words do in the following paragraph?
"And well, so I called her up on the phone, you know? And she um, actually hung up on me! Well I said, hell no, so I hung up on HER! But she uh, she called me! So I literally hung up on her AGAIN, you know?"
The only time something like this is acceptable is if your character isn't fluent in English ... or a teenager. After all, they don't add any meaning to the paragraph.
- Limit your adverbs. This is a controversial piece of advice from Stephen King, no less; he advises to use no adverbs at all. But he's referring to instances like this:
"I hate you!" He said angrily.
"Yeah? Well I hate you!" I said ferociously.
"I'm leaving!" He thumped the door noisily.
Etc. Total drivel. ;P Adverbs do have their uses, but only use a few and don't use them all the time. Obviously.
How do you know when you've used too many? Do a word count, and then find how many adverbs you have. If it's more than (say) 1% -- i.e. 20 adverbs in a 2,000 word piece of writing -- it may be time to cut down.
- He said, she said. In older books, authors used to use synonyms of "said" (e.g. "shouted", "yelled", "whispered" etc.) instead of saying "He said X" or "She said Y", or
"ABC XYZ!" he said.
This is totally unnecessary, and treats your readers like idiots. ;P If your character says "I hate you!" and your readers can't figure out that he's raising his voice -- shouting, yelling etc. -- then ... sigh.
You don't need to use the verb "said" at all, at least some of the time. You can eliminate it and use some other action. For instance:
"Oh, Marsha..." John fidgeted with his tie. "Do you truly love me?"
"Why, John! Of course I do!" Marsha twisted a blonde ringlet 'round her finger.
"Darling one!" John dropped to one knee, pulled out a small black box from his jacket pocket. "You don't know how happy you've made me!"
... Yes, yes -- it's schmaltzy as all hell, and not at all realistic. ;P Just mix your "said"s with actions, and you'll be fine.
- Last one, I promise: mobile body parts. This is a kind of weird one, but it's very logical.

See if you can catch out other writers (and yourself!) using mobile body parts, like:
She threw back her head and laughed. (This raises a strange mental picture of a woman throwing away her head ...)
His feet ran away with him. (Sounds like a man's feet leaving his body behind and running away)
He stole my heart away. (Ack! Not only a cliche, but also a mental picture of primitive heart surgery!)
... and stuff like that.

Anyway, I've lectured enough. What are some of your rules, hmm?