I was just thinking yesterday that most people would think I went way overboard with what I do:
1) Use MS Excel as a spreadsheet to track the big four and important lifts (e.g. pullups, shrugs, etc). One file for each 26-week period. One tab for each week, even when the page only lists "Deload Week" or "Vacation Week".
Reason: Automatically updates as numbers and percentages change, very easy to use formulas to automatically update percentages for the week; updates numbers when I change TM; very easy to copy/paste, so Week 1 of Program X can be pasted in at Week 4, and all I have to change is the TM.
2) I have a small notebook and pen that I write my workout during lunch, directly from the Excel file. I take this into the gym and mark through when each set is complete. I also track any joker sets or assistance exercises here, since I only do them when I walk in ready to run through concrete or when I know I have extra time I can spend there.
Reason: It really focuses me and gets me excited when I write in my notebook. It's something I've done for a decade now, since grad school, so maybe it makes me feel 25 again. Also, having the notebook to mark through completed sets helps me keep a routine so I don't waste time (90-120 seconds between sets) and so I'm always sure which set I'm on.
3) I have the GymHero app. It's come a long way, especially since the recent update last week.
Reason: It's overkill, but the timer is easy to see and it stores data in the cloud, so I'll have that there. It also gives me a breakdown of how much I focus on each muscle group and how much time I spent working out.
I definitely don't recommend anyone take this approach. My wife calls me a hyperfocuser. I have a few passions in life and I pursue them to extreme levels. I'm also reluctant to let go of what's worked for me, and this has always kept me motivated and in a rhythm.