you must have
2 actors(of 1 but reealy cool one)
a dropship and rocket and droppods would be realy a good think
at least 1 basic pistol
1 shotgun
1 sniper
etc
you must make them be 1 weapon for each job...
not the super anti everyting weapon of doom and mayhen...
and give them some kind of pros and cons(like they can dish out a lot of damage but they are fragile as hell or somthing like that)
give them a theme a standard color(any dark color is good blue green etc) and make them look like all the troops are fited with the same tecnology(hyper advanced of primitive)
AND TRY TO MAKE THEM BALANCED SO THEY WONT BE RAPING OTHER FACTIONS

Solace Inc. is generally accepted as a support faction, because it has stuff that nobody else has. If you can't do stuff similar to the set mould in good quality, then do stuff nobody else has/can do.

Though I started my Diemos faction with just one actor and a couple of weapons... I think making the actor a foot soldier guy, not some hero unit determines if the mod is treated as a pack or a faction really.

I think of it more of a support faction not because it's got stuff no one has (after all a regular faction can have innovation too ), but more that I'm skipping the stuff everyone has. To make a stand-alone faction that you could use against a vinilla factioned opponent you need to make a bunch of basic stuff; smg, machine gun, sniper rifle, regular rifle, pistol, shotgun... bleh. Just not that interesting for me.

... plus my spriting skills are average at best, and half the point of a faction is to show off your sprites. I'm more of a coder.

He pretty much said it all.

All you need is an idea for a theme/style and bang!... you can call it a faction. Also thinking outside the box and using some imagination can lead to some good ideas. For example, Darlos was making a "faction" based on energy blobs. Those energy blobs (flux) acted like the soldiers. So a faction can be anything, as long as it has a theme. Thats all to it.

The best way to come up with your aesthetic theme is to start with your functional theme.

For my faction, Asplode corp, my theme was cheap and nasty, so naturally my units took on a mass-produced and shoddily made look.

Think about how you play cortex command, and use that to create your function theme. make a faction for yourself. it can be pretty simple, for example capnbub's original crobo was an air-shock trooper, so it had a powerful jetpack and could take harsh falls, and his theme was simply 'futuristic', sleek and white. So don't worry too much, but try and avoid a theme of 'SOLDIERS HOO R GREEEN LOL'.

And before you get started, PLEASE don't make a faction with 'real life' weapons and/or soldiers. the only decent one of those EVER is the bear faction, and it's at least 50% fiction. this far in the future, AKs aren't going to be as popular.