Use the Vassal Module (it´s an editor too),
then you have not only the original terrain tiles, units and markers,
but also a lot of additional customized terrain tiles, units and markers
and a further big advantage is, you can use this setup (Vassal savefile) then also immediately to play it online with the Vassal Module.
Important: Setup your scenario as "Observer" and save it also at "Observer", to be sure, that the setup works also correct for online playing.
The most scenarios you can see here on this website was done with the Vassal module.
If you need more help, you can always contact me direct, if you see me online on CCN Vassal
Scenario pic is a screenshot, and then you import the pic and all the scenario rules to another document (general a Worddocument).
But you can also offer a scenario direct here, if you create a new "Scenario thread" and add there the picture and rules direct, see this example.
In this case it´s also nice, if you add the Vassal Setup too