As a regular traveller to Orkney (usually twice a year), I fly. Two flights each way, with possibly a stay in one of those airport hotels at Schiphol to catch an early flight. & I usually make it home on the same day on my return.
& everytime I try to plan the journey with the intention to avoid flying I give up. It always ends up with three days each way.

(I don’t really get some sleep on sleeper trains, night buses/coaches, intercontinental flights - a cabin on a ship is always fine, but then in my student days I worked on one, so you’ll have to learn one way or another


)
The puzzling of the possibilities always take sometime

& in the end of the day they were always rejected.
& everytime the puzzle gives different solutions even though
cost is not one of the parameters.
I do have some
flygskam, but this is a bridge to far.
& I did fly to Katowice a few years back for the wedding of an Orkadian friend. He said: oh you but you could drive there?

(12 h - just me on my own

). Train with overnight break in Berlin

All other journeys within Mainland Europe are made by train (& ferries of course

)