I use the RNG to find frames that will result in shiny eggs of the nature I am interested in, then I soft reset for good IVs after the egg is made. The directions are on Smogon
and are pretty straightforward once you have your Secret ID. Your Secret ID is a hidden value that makes a pair with your ID number and is what determines which frames on your game will be shiny.
Finding your SID is the tricky part of making shinies. There are several ways to do it. If you have caught a random shiny in that game, you can actually calculate your SID by hand using the information about that Pokemon. If you have caught at least 3-4 chained shiny Pokemon, you can do the same thing, although I would recommend using a Program instead of doing it by hand. Finally, if you (like me) have absolutely no luck with shinies whatsoever, someone who has an Action Replay or access to Pokesav can find your SID if you trade them a Pokemon from your game card.
Just contact me when you finish your game and want to try this, and I'll see what I can do. I can't help you find your SID if you have no shinies on the game card since I don't have an Action Replay, but I do know of some people who can.