Start with time, not a checklist
A first visit is easier to plan when you choose two or three regions and leave room between them. Hobart and the south, Launceston and the north-east, and the north-west and west coast each support several days of travel. Trying to cross the island for a different headline attraction every day usually means seeing more road than place.
Book the fixed parts first
Flights, the Spirit of Tasmania sailing, a hire vehicle and accommodation in busy periods set the shape of the trip. Add national park passes, booked walks and time-specific tours next. Keep some days flexible for weather, road conditions and discoveries along the way.
Build a balanced plan
Mix longer drives with local days. Combine a major landscape with a town, museum or historic site rather than treating every stop as a quick viewpoint. Check when to visit, getting around and how many days you need before choosing a route.