As you know (unless this is your first time here, in which case: “look! a new guy!”) I have been working on (and failing to make progress on) an Xbox Live Indie game called “The Cannon”. Once finished, it will be mid-range on development time and price (240 points, if I haven’t said that before, look I made an announcement!). I know some people following this may also be interested in how you’d go about making such a game, so here are some of my own pointers. This is mostly aimed at people who plan to do at least all of the programming on my own. If not, there’s a huge amount of other pitfalls that are explained in my degree course

Plan the whole thing in advance
Technically, this isn’t possible for the WHOLE game, cool things will come into your head later down the line and other things may need to be changed in order to get them to work. However, you need to plan through how everything you’ve thought of should work within the game, because if you don’t, it won’t be nice when you hit that brick wall.
Also, take into account how big you want it to be. When I started, the price points were 200,400 and 800, I originally set out to make a very high quality 200 point game. As the price points have changed, I stick around that price point and go with 240 as that’s what I believe it’s worth. However, this leads me onto the next point…

Start small…maybe?
To start off, the smart thing is to make a neat little idea in the 80 points bracket. Of course, the service is flooded with cheap little games, so if you want to make something to publish, try to be original with your ideas. If you set out to make something relatively big straight away, the length of the project will probably start to drive you nuts *ahem*. I would say I’ve spent upwards of 500 hours working on “The Cannon”, so it’s down to you as to whether you really want to have that sort of work up ahead of you.

Can you draw?
Assuming you start off with a 2d game (although the same principles apply to 3d), you should tailor the graphics of your game around your drawing skills. I’m just about content in my drawing skills, but that’s only because the enemies are so small. If you want to have half decent graphics, but draw like a flipper handed freak child (to coin a phrase from Yahtzee), then find a friend or someone else on the internet who’s willing to help out. Of course, if you go on to sell the game, they might appreciate a small share if they’ve done the graphics.
The same goes for music, in fact the ideal (small) game production team is one coder, one artist and one musician.

What do I need?
Most important information can be found on the xna website: http://creators.xna.com/. Programs, tutorials, information, forums, all the basic stuff is there.

and that’s that for that wall of text. I’ll add anything else later if I think it’s necessary, or alternatively, feel free to ask anything else in the comments.