An elevator pitch should be a pithy sentence that describes how your ideal customer is better off after working with you. It should not be about your inputs or processes. You don't want to provide a lot of info in your pitch, because you aren't trying to sell. You instead want:
1. If this person is your ideal client, then intrigue them enough to set a meeting for further conversation
2. The person can remember your pitch, so they can repeat it to someone they know who could use your help.
For example, a bad pitch is "I'm a great accountant with 20 years of experience who can help you." A good pitch would be "I've collectively saved my clients $10 million in taxes."