The plan was 100 push ups, and that is a fine plan. I was doing that for a while; 100 vanilla push ups. Then I branched out into doing half of my push ups near the center of my chest, and varying the angle as I went. I lowered the total number of push ups at that time, planning to work my way back up to 100. The funny thing that happened along the way was an odd type of success. I started developing muscles, but in a slightly odd proportion.
This is probably really obvious to anyone into fitness, as most people do a variety of exercises for a reason. But I'm still learning. So, my legs are fine. I do walk more than most. My forearms are actually fine too, developing a little during my time in pizza. The current issue that is only starting to develop is that my biceps and chest are starting to look out of proportion to my triceps and shoulders. So a little research, and it looks like the exercises I'm looking for are pull ups and chin ups.
There are actually a huge variation of pull ups and chin ups, depending on where you are gripping, the position of your legs, and even the muscles you use to pull yourself up. Figuring out which ones are right for me will a step, but not the next step. Step 1 was buying the pull up bar, which will be here in a couple days. Step 2 will be negative pull ups, because I can't actually do a pull up yet. A negative pull up is like a pull up, but where you only lower yourself.
It looks to me like push ups and pull ups can work every muscle from your glutes on up. So I'll will continue to do push ups, but I'll probably never return to 100 a day again. Partially because I don't want to spend more than 10 minutes per day exercising, and partially because I don't want giant muscles. The push ups I do might be deep push ups, since that is another use of the pull up bar I bought.
Which brings me to learning the ways of the hoop. That was where I bought a children's hula hoop, and failed to learn how to use it. That was supposed to work all of my core muscles. Step 2 was where I bought an adult's weighted hula hoop... and failed to learn how to use it. My rhythm sucks. The extra weight came with extra momentum, and it also had a little more grip. None of that seemed to help. I've heard gaffer's tape is one more thing I can try for even more grip, but I think I'm gonna put that on hold. Maybe I can find a teacher one day.