The not-quite-modestly-named Maxfield-Pack ratio comes from 101 Ways To Win An Election, in which Ed and I explain:

Maxfield-Pack Ratio From 101 Ways To Win An Election

Building up such a team takes time. If you want to win in May, now therefore is a very good time to start.

As to what to do to build up such a team, there is plenty of advice available from ALDC and, of course