Practice before you dial, then dial
Reading about selling on the phone does nothing until you have said the words out loud to a stranger. These drills get you to that point faster.
The technique
Practice in the order the call happens: opening ten times, then discovery questions, then the offer sentence, then the close. Do each aloud, standing, at the pace you intend to use. Ten minutes of this beats an hour of reading, because the thing that fails on a real call is your mouth, not your understanding.
Opening ×10 → two discovery questions ×5 → offer sentence ×10 → close ×5 → one full run-through end to end. Then dial immediately, while it is still in your mouth.
Sellers who warm up before their first call of a session convert measurably better on calls one to five, the ones everyone else writes off as warm-up.

What goes wrong here
Warm up, then take a live campaign tonight