You may want to ask your CDE or Endo. Mine said start on a 50/50 split for 2 hrs and see how that works. For most common meals it works well. I use a 60/40 split on sugary meals or meals with lots of up front carbs. Both work good for their given situation. The trick is getting all that protein/fat carbs accounted for. Once I did that and had a grasp on it, my numbers post meal have peen spot on.
Try and ask your doc about it. Also like I said, the TAG group here on TuD is an excellent resource. Step by step instructions, and worksheets and all that stuff. Here are some links:
http://www.tudiabetes.org/group/tagers
https://forum.tudiabetes.org/topics/dual-wave-bolus
http://www.tudiabetes.org/group/tagers/forum/topics/tag-your-meal-e…
Hopefully you can find some good info in there to start off with.