In terms of planning, I started with a Hornby oval of track, an 0.4.0 and three goods vans; like many of us, and aged 12. By 18, I'd had a standard 6ft x 4ft layout with Hornby BR stuff (I always had a soft spot for Class 31s). Then came an extended version of that, followed by a venture into 009 which was meant to loosely represent a CIE narrow gauge line somewhere in the West. That didn't survive a house move (my first), where a very large 009 set-up was built in the attic - my pride and joy until a damp problem and burst pipe bent all the baseboards and that was that. It was a substantial set-up, though never had scenery applied - not even platforms. It was meant for operational intrigue, which it had. That's gone now, a victim of two house moves in 20 years. The house in between had a G scale line in the garden for a while.
Now, Dugort Harbour takes shape by degrees. It's small - a shunting / fiddle yard thing - but hope springs eternal for planning permission for an extension......! For the first time in my case, it'll have high quality scenery. Currently, baseboards are in the hands of Baseboard Dave in Edenderry, and a superb job so far.
Point is - don't be put off if something that you initially plan doesn't live up to what you expected. Like Robert the Bruces' spider, "try, try and try again". As others have said, doodling station plans on random bits of paper passes the time and fires the imagination, and the planning is part of the journey.