There are three versions of the lasso tool:
Tip: “Ctrl & D” gets rid of the lasso tool selection.
The regular lasso tool is good for creating irregular patterns or shapes. Anything you want to draw freehand eg. a puddle on the floor.
The polygonal lasso tool (as the name suggests) is best for creating polygons. If you hold down “Alt” while using this tool though it reverts to the regular lasso tool (ideal for shapes that may have three straight sides & then a wavy fourth for example).
Tip: “Backspace” will get rid of the last click of the lasso tool without having to start all over again.
The magnetic lasso tool is used for tracing around objects. There are three adjustable controls within this lasso tool. Increasing the “frequency” will create more points around the object. However, too many can make the selection become jagged (50-60 is probably a good amount). The “width” setting dictates how far you can move the cursor from the edge of the object & still attach a point. It’s a good idea not to have this set too low. Finally, the “contrast” setting sets how much leniency you have from where you click & where the computer thinks you should put the point. A low value will place it exactly where it thinks the line should go (hence, a slightly higher value is preferable).
Once you have your selection you could add an adjustment layer & change the objects colour.