MOC planning and design What tools do you use when planning and designing a new MOC? Pen and paper? Or there is something more advanced?

I had the insane idea to try LDD to design my MOC and it was a nightmare.
Since my MOC uses sets from castle fantasy, there are maybe 3D models ready to use for LDraw or other kind of software suitable for this task?

EDIT: I will go into further details to explain my issues better.

This is the list of sets I want to place in my MOC:

Fantasy Era:


7036 Dwarves' Mine
7094 King's Castle Siege
7079 Drawbridge Defense
10193 Medieval Market Village
7037 Tower Raid
7029 Skeleton Ship Attack
7048 Troll Warship
7097 Trolls' Mountain Fortress
A lot of smaller sets like 5614 The Good Wizard that do not take space.


Kingdoms:


6918 Blacksmith Attack
7187 Escape from Dragon's Prison
7188 King's Carriage Ambush
7189 Mill Village Raid
7946 King's Castle


I want to build a nice terrain where to place all those sets together. for example, a mountain where to place the Mine, and a hill to put the Blue Castle on top. The a river for the Drawbridge, a plain for the medieval village and the the mill, a coast for the harbor, a sea for the two ships, and another coast for the Troll fortress. I have yet to decide where to put the Red castle.

The whole MOC would require 10-14 big baseplates (my estimate). So planning the whole thing is very hard and I got lost with LDD very soon. To make things easier, it would help a lot if the software has the "size box" for the sets, so I have a way to understand how to place each set on the scene without having to build them from scratch, so I can concentrate on the terrain.

I have no clue on how to go forward on this, to design all the terrain and then get the component list (and it's cost) to build everything.
Some of the more popular programs used when designing MOCs are:


LEGO Digital Designer
MLCAD
SR 3D Builder


There are some other ones available but those three seem to be most preferred editors. They all have quite similar set of features but their user interfaces are very different. I encourage you to try each of them out. If you wish to find most extensible software, MLCAD seems to be rather old and stable platform to build upon.

I myself use pen &amp; paper for concepts and ideas and LEGO Digital Designer for designing.