There have been a large amount of "Wouldn't it be cool if..." threads lately, so I thought I'd help out and provide some tips to make your dreams come true.

For a start, know that there are no machines that look at your request and dutifully spit out finished mods. You are requesting the time and effort of modders, regular people like you who have jobs, lives, and other interests. You have no right to demand something be made, just as you have no right to demand that your neighbor next door paint your house (there are exceptions to that example, but you get the picture).

This leads to point no. 2. If you want things to get done, provide incentive or offers to help. Idea men are great and all, but it doesn't put the bread on the table if you get the metaphor. If you really want something done, provide sprites, code, or money. A motivated modder puts out better quality work.
Addendum: Provide an idea of what the heck you're requesting too. A gun or character famous in an anime you know might not be very well known to everyone else who travels this way. Pictures, a description of the character and/or their abilities, and the like are essential.

And finally, point no. 3. Lua coding is damn hard, and it can't do everything. Lua is the magical promised language given to us by Data and that guy who actually implemented it, but sadly it is not all-powerful. That power is reserved to Data since he has the source code. You can do damn cool things, but be prepared to be disappointed if you ask for outlandish game mechanics or convoluted effects. You are far more likely to get something if you ask for simple ini-only mods than if you ask for Lua mods that do X, Y, and Z. That said, if you can make a kickass Lua script by yourself but need someone to do the sprites and ini coding, you're much more likely to get a mod than those who don't do anything for their request for an ini-only mod.

With those, that is the basics of requesting. Put them into practice with a grain of salt. Even if you follow all of the above, there is still no telling whether you'll get a modding team to fulfill your request. You have to trust your luck and hope that your idea piques the interest of our population.

This needs a sticky.
Nice to post it too.