Preflight planning consists of three or four basic tasks

Planning the route
Checking the met
Checking the Notam
Filing any necessary paperwork: Flight plan, Customs, Special Branch, GAR

If you are looking for best practice I’d guess Olivia is just about it.

Oh for a UK versions that was as good.

Virtually all my route planning is done offline with Navbox Pro. The ability to drag routes around on the map. Plan a load of alternatives and then squirt them straight into a portable GPS makes it indispensable for me.

Moggy