I walk to the station, train to London and bus to Holborn. But if there is a transport SNAFU that I am aware of before leaving home, sometimes I walk to another station and Underground from there. Door to door time is usually about an hour each way, though can be as little as 50 minutes with perfect timing (rare) or up to an hour and twent, twenty-five minutes if London Midland has messed up or they've dug up Southampton Row again.