I just log everything in a book. I write my workout in pen, I leave a box to write my weights in and a box to write my reps in. I carry a mechanical pencil with a rubber on the end. When I finish a set I rub out the target I had given myself and write my target in for my next workout based on what I just achieved. It literally takes seconds.
I keep my phone in my bag as if I take it out I’ll end up on social media or googling, “how fast does hair grow” or some shit like that.