This page is great! One thing to note is how little analysis work is required these days. One just needs to know basic things like Ohm's law, where to start, an

This page is great! One thing to note is how little analysis work is required these days. One just needs to know basic things like Ohm's law, where to start, and how to read datasheets. But, it's missing 2 things: 1. Microcontroller selection. This can be a daunting task. Best to just pick one with good dev kits and community support. You can tailor the part number if you need more IO for a specific project. The only real choice to make is if you want/need to work in the low-power embedded realm (eg Arduino or STM32), or in higher-power/userspace realm (eg raspberry Pi or Beaglebone/Linux). 2. Rules of thumb for the design. You mentioned some great ones. I would add - use 4 layers unless you need more (and you will know if you do) - Put signals on the outer layers so you can access them for troubleshooting, unless you have a reason to have ground planes on the outer layers (you'll know if you do) - Use the internal 2 layers for ground and power. The keyword "polyfill" will let you know how to do this. - Don't try and make PCBs at home. It's so fast and cheap to order them. And a home-made one, even if you make it with a router instead of the printer/acid method, will not have a solder mask. You can easily spend 3 days troubleshooting. Watch movies for 3 days while you wait for your delivery, instead. - If you have any doubts, use a breadboard for prototyping. If you have confidence on your 3rd board design, skip the breadboard. - Put a hole in each corner, with a healthy clearance from any circuit to a fastener. At some point you will want to mount the PCB somewhere. - Put some spare IO on a connector if you have space - Use a barrel connector or USB for input power if you can. If you need more than 5V, USB-C at another voltage is trivial to add these days (as this page shows). It's a matter of when, not if, you mess up your settings on your bench power supply. - Use 2.54mm pin headers where you can instead of weird connectors - Ask yourself: Can I buy something that will work instead? - Invest in 3 kits: surface mount resistors, surface mount capacitors, through-hole resistors. eg: https://www.sparkfun.com/products/10969 https://www.sparkfun.com/products/10969 - Spend at least $100 on a soldering iron with temperature control