Here is a link to a site with details about selection in Photoshop …
First there is the Marquee tool (M) which comes in 4 different varieties.
Add “shift” to make the shape drawn proportionate, “Alt” to create it from the centre …
In the Options Bar at the top of the window, one can control the selection in various ways such as Feather, Style and Size. There is also a “Refine Edge” tab.
The “M” tool though is rather basic.
The “L” or Lasso tool is slightly more complex; there are 3 forms.
The basic form allows one to draw the selection while the “polygonal” form works by creating points – they can work as one tool with Alt
The Magnetic Lasso tool is more automatic and can be refined via the Options bar.
The “L” tool is not that accurate unless the edge is well defined.
The “W” or magic wand tool is a bit cumbersome; however, with Refine Edge it can do a decent job. Controls with W are …
Tolerance – relates to the sensitivity of the colour selection
Contiguous – ticked it will only select pixels in one group; un-ticked it will select all areas of similar colour
Sample All Layers – clicked, the selection relates to all possible areas on all layers rather than just the one selected.
W is rough but ready; other tools can make finer selections.
The Quick Selection tool, also W, is however much better at quick selections that can be drawn with a brush. Combine with Refine Edge for accuracy!
“Color Range” is like a non-contiguous Magic Wand; it’s accuracy can be altered via the Fuzziness slider. There is a black and white preview of the selection. Not a very effective tool.
“P” is the Pen tool and requires a certain amount of skill; good for accurate selections where there is a clearly defined edge. Can be saved as a selection.
For fine tuning a selection, a mask is a valuable method. These can be altered with the brush tool (a mid-grey selection will help to make the brush an easier tool to work with). The brush can be either hard for well defined selections or soft for less well defined edges.
Working with channels can also help to make selections more accurate; using other controls such as Levels adjustments, dodging and burning etc One looks for a channel with higher contrast around the object one wants to select and works to increase that contrast for selection purposes; one is likely to have to increase that contrast which means copying the channel. Inverting selections is often necessary.