To be honest some days I have trouble hitting my macros, so I do my best to hit my protein target for the day and eat fat to satiate myself. Even on the days I somehow go over I'm not too bothered because I don't hit my target completely most days.
I used a Keto calculator, added in my stats (ie weight, eye-balled my BMI - obese like a motherfuc.er - amount of exercise per week) which gave me my ballpark daily protein goal. Then I added in how many carbs per day - I keep it under 23g. The rest of the calories is made up by your fat amount. You can increase or decrease this according to how much of a deficit you want to eat at each day. Obviously higher deficit - increased weightloss. I didn't overdo it, I think I was around 30%, but I can't recall exactly how much. The calculator gave me a 0.9kg/week loss at my percentage.
Also, I had to remember to change my goals according to my new weight every so often.
This is my main concern. When I'm lifting I don't know how much extra protein to add to my diet. I use Whey, so I have a post-workout protein shake, which is around 25g protein I think.