Many grammarians advise that starting a sentence with ING words—in this case used as participles—is the weakest way to begin a sentence. I wholeheartedly agree. ING words create phrases which can cause written nightmares in our work.
The reason writers should avoid beginning a sentence with an ING word is threefold.
The first fact is that too many sentences starting with a present participle (an ING word), pound a harder pattern in the reader’s mind and will echo with other INGs even when a different participle is used. (ING words also echo when it’s a gerund rather than a participle. Avoid echoes.
Singing as loud as she could, Jolene …
Trying to gather her thoughts, Jolene … (This also a bad start because this phrase would be more effective if shown rather than told.)
Secondly, just as amateur as creating echoes, writers sometimes create dangling modifiers. Because these danglers can sound natural to the ear, they are not always easy to catch. Many people talk with dangling modifiers, but they don't notice because the listener knows what they mean. That's not true in writing. A dangling modifier is when the modifying clause isn’t given the right subject in the clause that follows. à Looking at her shoes, the toes were scuffed up. It is the character who is looking at the shoes, and the first word directly after that comma ending the modifying clause should be the noun or pronoun of the person doing the action. Looking at her shoes, Jolene frowned at the scuffed toes.
Ask, who is looking at her shoes? Certainly not the toes of her shoes.
I sometimes make dangling modifiers when I revise, because though windy, my original words are what I meant, but then I try to tighten and change one of the original clauses. Sometimes in my haste, I forget to go back and look at the other part of the clause. If I don't read the entire sentence again, I'll leave a dangling modifier that will humiliate me later. :-)
The last situation concerns logic. Participle phrases often create an oversight in logic when writers want to show a character doing two things in one sentence. Make sure they can actually do both actions at the same time.
Here's what I meanà Grabbing her purse, Jolene carried the antique relic carefully with both hands and ran to the bus stop.
If both hands are busy, she can't grab her purse with one of them. The two actions cannot happen at the same time, or at least are very unlikely to happen at the same time. (She might be grabbing her purse with her foot, but I doubt it.)
Note there is a subject in the second clause, a person doing the action, so this is not a dangling modifier; but it is a mistake, nonetheless.
It is those three situations that push grammarians to prefer writers avoid participles at the head of a sentence. It is those three problems that give participle beginnings a bad rep.
That does not mean never use them. It means if you do use them, do it sparingly and make sure they don't create echoes of ING words starting your sentences; make sure they do not dangle without a subject to hang on to; and make sure they do not create an illogical meaning.
And a final reason, not attributed in the threefold analysis above, is this: most authors, editors, and publishers recognize that a newbie's way to attempt avoiding the overuse of "as" clauses (she did this as she was doing that), while at the same time showing two actions in one sentence, rely on present participles to begin their sentences. Likewise, they do the same to avoid multiple sentences starting with he or she or a character’s name.
So in a nutshell, the use of an ING word often means the writer didn't know how to avoid an "as" clause or the overuse of pronouns or a character’s name. This makes the writer look amateur. Check your writing for these mishaps. Also check your favorite authors and see what they did to avoid the problems.
When you start sentences with ING words, read through a page at a time out loud. Do you hear a pattern/echo of too many ING beginnings? Is your second clause missing the person/thing doing the action? Have you created a scenario that doesn’t hold up against logic?
One final note on participle phrases. I have a dear writing friend who shares in critiquing work through a writing group we attend. She marks every ING word as a dangling modifier. Not all participles dangle. Also, be aware that even some ING words that start a sentence are not modifiers; but rather, they serve as the subject of the sentence, or at least part of the subject. When an ING word is the sentence’s subject (or part of the subject), it is not a modifier; it is a gerund.
Racing to her car, Jolene held her purse tight against her. (Participle phrase. Racing to her car, more specifically “racing” modifies the noun Jolene)
Racing to her car was Jolene’s only hope of escape. (Gerund. Racing to her car is a phrase and the entire phrase serves as the subject of the sentence.)
I hope these tips help. Happy writing!