I started my game again today (we bought the official handbook too) and I already found a shiny Scatterbug, now I have a shiny Vivillon on my team.

I'm going to try a rotation team of 18 Pokemon, with Exp Share hopefully it will be easier than I think.
I'm just about to enter Lumiose City for the first time and my team is Frogadier (Lv 16), Vivillon (Lv 14, shiny) and Combusken (Lv 17).