There is a variety of selection tools available within Photoshop, and they all have their area of application.
Perhaps the most difficult to use, and the most time consuming, is the pen tool, where you painstakingly draw an accurate boundary around the parts of the subject that you wish to work on.
I came upon the pen tool quite late in my PS career, but I regard it as being one of the most valuable selection methods, as it can accurately select to the nearest pixel.
You can use the pen tool in conjunction with say the Quick Selection tool, tidying up edges that have been missed, or ensuring that a straight line is indeed straight.
I normally work at either actual pixels view or one stage of magnification above that when using the pen, in order to ensure an accurate selection.
There is a learning curve, but take heart, it's worth persevering. As with most things in PS, you can easily step back if you make a mistake.
Where do I use the pen tool?
It provides a nice clean boundary for a cutout (when you want your object surrounded by, normally, white space)
To preserve a section of an image when cloning, particularly if straight lines are involved. You pick the bit that you want to keep, and then select the inverse of your selection. Any cloning will then not impinge upon your important area.
To improve the accuracy in drawing a layer mask.