I use them in first drafts and let the writing flow, but I suggest in final drafts only keep them on the last page or other pages at a minium, for inpact, if you must use them
A horror scene
...He leant towards her slowly and whispered, "Goodnight sweet heart," before he quickly picked up the heavy knife
Same line written without them.
...He leant towards her and whispered, "Goodnight sweet heart," before he picked up the knife
mmm, I think it has to do with impact, and if they were only used as they are in the first example after not being used elsewhere, it would have much more impact than the second example. A sentence without them reads differently then with them. But if your dialogue contains all that is necessary then you don't need them, but sometimes it will still read better with them.
He leant towards her and whispered, "Goodnight bitch," before he picked up the knife
Now, well, I don't know but lets try a love scene
...He leant towards her slowly and whispered, "Goodnight sweet heart," before he quickly picked up the condom
He sounds like a jerk the line above...he's going about it all too slowly to start with and too quickly near the end.
...He leant towards her and whispered, "Goodnight sweet heart. Do you want a bit?" before he picked up the condom
lolol I should go to bed. But they should be used sometimes and not others. Only the writer of the piece can decide the best time to use them, and readers will revoult if they are used too much.