Joe The Contractor uses THUMBNAILS as BLUEPRINTS to DIRECTLY create selections.
Major tool of the trade: CTRL KEY
CTRL + Thumbnail – to create a selection based on the following layer thumbnails:
TIP: If you used the SHIFT or ALT key along with the CTRL key, you can ADD or SUBSTRACT from an EXISTING selection on different layers, respectively. If you used both the SHIFT and ALT keys along with the CTRL key, you will create an INTERSECTION with an EXISTING selection on different layers. You can also do the same concept with alpha channel thumbnails.
TIP: If you have MULTIPLE "objects" on a layer with transparency, you can add any type of selection around a single object and then CTRL+ click the UP arrow instead of the thumbnail to select just that SINGLE object.
Scenario: Once Joe The Painter finish his drawing. Joe The Contractor is hired to use blueprints to complete some of the projects.
As a contractor, Joe The Contractor has to "wear many hats" and as a result he will use a combination of tools (Selection, brush and pen) to get the job done. The rule is the RIGHT TOOL FOR THE RIGHT JOB. Even though you have a power tool, like the quick selection tool, it may be more effective to use a simple tool, like the rectangular marquee tool to draw a selection around a rectangular object in the image.