Danglers have an evil reputation, but it's mostly unfounded. It's true that they tend to scream horrible things about the standard of literacy and the intelligence of the perpetrator, but, hey, they very seldom cause any physical damage.
Avoiding danglers is mostly a question of thinking about what you're saying, and then saying what you mean. Or, if that's too difficult (and it can be) then using very short sentences does the trick. (I must here admit that this was my technique when writing my first published novel, Cold Tom. Several reviews remarked upon the stark concision of the style, too, so that worked nicely on more than one level.)
Anyway, what's a dangler? It's when you begin to describe something, but then you feel the need to use a comma and the sheer stress of it leads you to switch to describing something else.
Leaving the house...
okay, so next we're going to be told who or what was leaving the house, yes?
...the lamp post could be seen shining brightly.
Hey, but you can see what was meant.
Driving along the coastal road, the dolphins flung silver sprays of water into the air.
A point worth making is that there's nothing wrong with either of those sentences if that's what the writer meant. But it probably wasn't.
Six feet tall and built like a gorilla, she decided the truck driver might help her.
Covered with flowers, Fred was sure his entry would cause amazement.
Shining with slime, Holly watched the snail crawl over the pot.
Do danglers matter?
Well, yes, sometimes. If Holly in the last example is in the middle of a horrific adventure then a snigger will destroy the carefully-wrought atmosphere. Some potential danglers, like hopefully, though, are used so commonly, though, that no one is going to notice them. Hopefully, the vicar will give us a short sermon.
To make the point again, people only end up in knots if they make fancy loops in their sentences.
And, hey, you can even on occasion establish some sort of a literary reputation by keeping things plain and simple.
Word To Use Today: dangler. Dangle is a Danish word which it seems we've borrowed. It is said to be imitative, which is a bit odd, though I think I can sort of see what they mean.