Option 1: LEDs in parallel with single resistor (two different layouts).
This is not the preferred approach according to several other people and websites.
Each layout pulls 60mA from the power source.
Can survive LEDs going out as long as the remaining LEDs can withstand the increased current (60mA \ # of remaining LEDs). If two LEDs fail, the remaining LED will need to withstand the full 60mA itself.
Option 2: LEDs in series with single resistor (two different layouts).
Least expensive method, but has a single point of failure.
Each layout pulls only 20mA from the power source.
Cannot survive any LEDs going out since they are in series.
Option 3: LEDs in parallel, each with their own resistor (two different layouts).
Most reliable, but most components and most complex (of these three).
Each layout pulls 20mA * working LEDs from the power source.
Each LED can survive the others going out and will maintain the same 20mA pull they had before others failed.
...I was also validating for myself that resistors can be before or after LEDs.
