Travel to Scotland from Amsterdam area via Train or Ferry

I had friends that took the train from Amsterdam to Newcastle and then took the train north from their to Inverness. It would be shorter to Edinburgh. There are other ferries. You could also explore the Eurostar. When I made this trip myself with friends from Amsterdam, we flew to London and connected to Edinburgh. We caught a train north from there. They flew through Heathrow, I flew through London City and we met up in Edinburgh.

You can fly direct from Amsterdam to Edinburgh on EasyJet for $100. Or DFDS Seaways runs an overnight ferry from Ijmuiden (Amsterdam) to Newcastle, England

Thank you all for your responses. Very helpful