They say that excess protein will cause glucose neogenesis in the liver, with almost half of the excess being transformed into glycogen. Now that I am older, I am much more sensitive to carbs and protein, and I find that lowering my protein intake is helpful in maintaining nutritional ketosis.

This website has a Keto Calculator which gives you an idea of the macros you need to consume to stay in ketosis:

http://keto-calculator.ankerl.com/

That, and my ketone meter are very helpful. I am a firm believer in testing, although the strips are 2 dollars a piece. Some are even higher at 6 or 10 dollars.
But now that I am no longer eating out, I spend the money I saved on the keto strips