-Rather then giving each actor specific classes, skills, etc, I like to leave a lot of that work up to player preference. I like to use stat distribution scripts, so the player can set their own skills rather then me stressing over if my character may be too epic or not. Same with classes - I only use a few, and then I use a class change system. Or even let the player choose their own class. You may even consider letting them purchase skills, using a skill shop. Some of this stuff can be done with eventing, so using scripts is optional for those who don't want to :)
-Keep a "to-do" list of any bugs, or things you need to tend to.
-I read on another post here somewhere that making the most original game out there is not exactly easy. So, don't try too hard or beat yourself up over that. Try to use an idea that may be semi-original, but add your own twists and turns that make it transform into it's own thing. That's my opinion. :)
-Also, another thing I read somewhere. Try to keep a general grasp on your story. Don't be afraid to add little twists to make it more interesting, or things that may not even be all too relevant. I've noticed many FF games add random stuff along the way, kind of like real life. The game can't always focus 100% on the story, but should always go back to it. Side-quests help quite a bit here. xD
-Use effects. Throw in lots of things that make the game very interesting. A good example, in my opinion, is Omegaz (i think that's how his name is spelled?) quest demo. I laughed my butt off while playing that demo, even though shortly afterwards I learned about MA's quest system.