I posted this for another player, but thought to include it here as its own post so people can easily create scenario templates drawing from the SINS Vanilla GalaxyScenarioDef file located in their GameInfo while still using GalaxyForge 1.0, which imho is overall a much better mapping tool than GalaxyForge 1.1 that does not currently allow for easy template placement or even viewing (crosses fingers for next release of GForge).

The standard scenario template can get pretty complex when you start tweaking things and might even break the map if you enter things wrong.  The other issue with scenario templates is that you need to start galaxy forge 1.0, then save your map -without editting anything, then open it in notepad to write the scenario templates you want to add to the map.  If you make small maps with only a few scenario templates, your work is pretty easy.  If you make large maps with lots of definition (many scenario templates), then you have a lot to do depending on what you want to add.
Once you get the hang of the scenario templates, the universe can take on extraordinary definition and depth -which of course is directly proportional to your own creativity.

MODDED HOME scenario template : a scenario template that once added to a world gives the planetowner a frigatefactory, combat lab, 2 noncombat labs, capital factory, 1 battleship, 3 light, 2 LRange, 1 siege, 1 AF, 1 colony frig, 3 carriers, and 3 heavy cruisers.

The structure is as follows:
template 1 = as this is the only template added to the map, the number is 1.  If you have more than 1 template, then the number must correspond.
template = tells SINS the template begins now
templateName = the name of the template, "MODDED_HOME" being the name of this particular scenario template.
subTemplates 0 =I just leave this alone at all times.
groups 3 =in this case there are 3 "group" items, if you have more "group" entries the number must be the same.  like in the case of a militia with 7 groups and probabilities of spawning, the number would be 7.
group : tells SINS the group begins here
condition = tells SINS the type and param
type "PlanetOwnerIsRace" = If the planet owner is race, check param, then items will spawn for that race.
param = in this case Tech, Psi, Phase (races).  Together the condition reads, "If player race is 'Tech, Psi, Phase", then items will spawn accordingly.
owner = in this case items will spawn for the planet owner, not just for a particular player.
colonizeChance: 0 or 1 : no or yes.  Does what spawns control the planet?
items 22 : the number must match what is listed below it, if not the map breaks and you must change things to match.  This basically states that X number of items are in the group. 
item "" : within the "" you insert the text found in the aforementioned "template list" text file.
**If the number of item "" does not match the number in items X, the map won't load.**

Examples of scenario templates
7DS Systems of War ULTRA (for SINS 1.05 or SINS 1.13) UPDATED 2/16/09
The scenario templates include: MODDED HOME, Vasari Militas (very weak, weak uncolonizable, weak, medium, strong) and LightPirateBase. 

Within GalaxyForge 1.0, the ScenarioTemplates seem to double up, this is a minor glitch in GalaxyForge 1.0, but you can use either repetition without issue by double-clicking a planet, then clicking "ScenarioTemplates" to see them.  Then add the template to the world and uncheck "Use Default Template".  Woot, you now have a world with your own goodie added instead of whatever default TEC militia usually goes there.

By the examples given in this map, you should be able to figure out how to (with the item list) change what the players start with (add a siege bs, add more labs, refinery, more frigs, cruisers, etc...), change the militia to either completely Psi (advent) and/or change what spawns for said militia (maybe replace the vasari militia with pirate ships for a universe in which the pirates have decimated the vasari worlds -leave vasari structures, add pirate vessels).  You might even beef up the pirates by adding a TEC capitalship or maybe you want the pirates to have some captured Psi and Phase vessels.

Always Colonizing Militias
examples: VasariGathering & AdventCommune
For a militia that always colonizes, change the first group in one of the Vasari Militias to: (don't copy/paste or you'll mess up the structure -forums doesn't like tabs)

 group
  condition
   type "Always"
   param ""
  owner "RandomMilitia"
  colonizeChance 1
==================
Doing this means that a random militia will always colonize the world to which they are assigned, that the ships/structures for that group will always spawn, but the other groups where type = "PlanetOwnerIsMilitiaWithChance" still have a chance of spawning.  The other groups with type = "NoPlanetOwner" or "NoPlanetOwnerWithChance" will be ignored, so you might want to name your revised template "VasariControlled_X" where X = weak, medium, strong, city, etc...
For this type of "Always Colonizing Militia", you might want to add more of the "PlanetOwnerMiltiaWithChance" and param between 0.0005 and 0.1 (almost never spawning to rarely), 0.15 to 0.45 (moderate chance of spawning), 0.5 to 0.75 (darn good chance of spawning) and 0.8 to 0.95 (almost always spawning).  Rare should be pretty powerful, and the almost always spawning what you almost always want to spawn.  Becareful, if you have 18 groups with param ranges set high, they might all spawn making the world incredibly difficult to assault (the Ai might never advance into it due to faulty AI behavior)
I hope this helps you create some interesting universes and then crush them under your iron heel. 

-SamazRalan

Since I am part of the developer team for 7 Deadly Sins, I must give a plug for the mod because the scenario templates included here are standard templates for 7 Deadly Sins.  Galaxy Forge 1.0 will be bundled with 7DS 2.0 Final.

will have a fully customized GalaxyScenarioDef complete with many easily placed structures allocated along racial lines, fleet additions, planet defenses, more militias (Tec, Advent, Vasari, and Empire), heavy patrol fleets with at least 1 capital ship, and heavily colonized worlds with many structures and a sizeable fleet defending it from warmongers, crusaders, and plunderers.

TEMPLATES AVAILABLE AS OF 7 DEADLY SINS 2.0 (near final) -click to larger image.

**7 Deadly Sins : Systems of War : ULTRA** Updated -includes VasariGathering and AdventCommune Always Colonizing Militias.

7DS Systems of War : final touch made in GalaxyForge 1.1 for compatibility with SINS 1.13