This page and child pages will attempt to go over the major considerations when choosing items to use with hardware.
The general approach is as follows:
What specifications are given
Digikey filters or datasheets are a great place to start
Find out why those specifications exist, if applicable
FBSOA, Wire amperage, fuse voltage, etc.
How do those specifications affect your application?
Eg: Voltage drop, Power dissipation, frequency limitations, etc.
If there is a specification given that you do not know about, you MUST figure out WHY it exists in order to properly spec the component, or find additional cost savings.