A couple of practical points
Edith Evans once said she drew the line ending to her like a golden thread. Be aware of line endings and alight upon them.
If you drop the ends of thoughts or lines or give them a downward inflection it means there is no ongoing energy. By alighting upon the line endings you get a much stronger purchase on the first words of the next lines.
Where do you breathe and where do you pause? My answer is that you can pause anywhere you like, for as long as you like, so long as it’s at the end of a line. And if you pause, then you can breathe! Here’s a quick example from Henry V. The situation is the morning of the battle of Agincourt. Everyone is terrified. The king overhears one of his followers
York O that we now had here
But one ten thousand of those men in England
That do no work today!
Henry V. What’s he that wishes so?
My cousin York? No, my fair cousin:
If we are mark’d to die, we are enough
To do our country loss; and if to live,
The fewer men, the greater share of honour.
First of all, the king completes York’s half-line with the question “What’s he that wishes so?” So, no pause, straight in on cue. After that Henry can pause as long as he likes. He has everyone’s attention; they are waiting to see how he will react. Will he lose his temper? Will he agree, which would send out a dangerous signal to the troops? Or perhaps he will move straight on and answer his own question with “My cousin York?” The pulse carries on, “No, my fair cousin”. No break till the end of the line. You can pause there if you like, though it mighty get a bit ponderous. There follows a counterpoint of “to die” and “to live”. You probably want to run over the line ending of “enough” and move the next line straight through to “live” to completer the apposition, not pausing at the semi-colon. Then you can pause which allows the troops to speculate on the prospect of “to live.” Then you give them the really positive signal: “The fewer men, the greater share of honour. “ So the pauses and the breathing can be used dynamically to aid the drama. It makes the other character and the audience want to know what comes next. So of course they listen more intently.