If I create a component in Model #1, how do I save it and use it in Model #2?
Select it, R-click, and Save As… to somewhere you can find it, then open Model 2 and use File/Import to bring it in to Model 2
You can also make a custom collection in the Component browser and save it there, which will make it available through the browser for any model. But I use John’s method quite a lot and just have a folder of models / components for a particular project.
I use Peter’s suggestion and create local collections for components so I can sort them by type. Then when I make a new one I can just drag it from In Model and drop it into the collection right in the Components panel.