The value of role-playing
The only thing salespeople hate more than cold calling is role-playing, yet it is the single fastest way I know for a salesperson to see what they are doing wrong on the phone and fix it.
Source: Sales trainer Michael Pedone
Of course, you will need someone with experience who can correct your mistakes (having two struggling salespeople critique each other in a role-playing session is pointless). So make sure you have a top sales rep or even the owner of your company, if possible, sit in and give you advice. It will be uncomfortable at first, but you will see the pay-off in short order.