Pinecone
En-Route
In the Piper what I usually do is, engine start, run-up and takeoff on the fullest tank. If both are the same, I just pick one and then keep flying on that tank until one hour total since engine start. Then I switch to the other tank, stay on it for an hour.
How do you know that the second tank will feed?
My Mooney POH checklist has you start and taxi on one tank, then switch for the runup. So you know both are feeding.