First, get a female starter. It can be any starter as long as it's female. Now progress through Pokemon Black until you can store 2 pokemon in the daycare center. Now, catch a shiny male Deerling and evolve it into Sawsbuck. Put your female starter and the Sawsbuck in the daycare center and keep hatching eggs until you get another female starter, except it has to be shiny. Now, fly to Nuvema town and stand in front of Prof. Juniper's lab. Save here. Then, walk into her lab and walk back out again 50 times. On the 50th turn, when you walk back in, she should be in the lab. Save here. Then, switch the shiny starter to the fist slot in your party. Talk to Prof. Juniper. When she sees the Pokemon, she will praise you for being so determined at hatching a shiny, and she will give you a device so that when you turn it on, you will run into nothing but shinies! (When it is off, normal chances for shiny wild Pokemon return)
...I wish