I do this all the time. I've gotten used to judging how I feel in the morning, and determining from that how much to take.

You really can't decide by how much difference you feel right after taking a caffeine pill. If someone is going to keep taking one every 10 minutes until it kicks in, that would be deadly.

There's a short lived placebo effect, then half an hour to 45 minutes later, after I've forgotten whether I took one or not, my energy suddenly ramps up. If I've taken more than I need for the day, it's a bit of a ride that I just have to hang on for, it's not going away until the chemicals are done doing chemistry with my brain.

There are also slow-release caffeine pills. It's a slower, smoother ride up and down the energy boost, and more analogous to sipping a caffeinated drink through the day. But without needing to pee 2 or 3 quarts of water that would come with sipping enough drinks to reliably get 100-200mg of caffeine out of it.

I tracked down pills because I can't stand the taste of coffee, so the whole ritual thing is ruined because I hate the stuff. Tea seems more variable in dosage, and energy drinks or Mtn Dew are too expensive both upfront and in long term health expenses.