Cornwall beat Hertfordshire 45-28 on Saturday to top their pool and stay on course for a third title in a row.
It is the fourth time in the past five years that they will meet Lancashire in the final of the competition.
"We know what they bring. They've got a good coaching set-up and obviously they know what we can bring," Shepherd said.
"It's a battle because we know last time we played them it was 18-13, so we're looking forward to the challenges ahead.
"We've got to really nullify what we know they can do."
It is the fifth year in a row that Cornwall have reached the showpiece final, with Graham Dawe's side losing twice to Lancashire, but beating them most recently in 2015.
"We've obviously not achieved anything apart from three wins, so we'll still got a final to prepare for," ex-England hooker Dawe told BBC Radio Cornwall.
"This Cornwall team - it's a good team, it's a fresh young team, but they certainly know how to play for each other.
"They defend like a bunch of tigers and full credit to them."
Scrum-half Matt Shepherd says Cornwall must "nullify" Lancashire if they are to beat them in Sunday's County Championship final at Twickenham.