Method 1 - Pen Tool:
Select the Pen Tool from the Tools on the left. It's easier if you zoom in to your image and start to create a new work path by plotting Anchor points along the outline of your subject.
Once you have closed the workpath, go to Paths tab and you will see your newly created workpath there. Ctrl-click on the workpath layer to load selection. Select > Inverse to select the area outside the subject. Press Delete.
Method 2 - Extract Tool:
Open up your image and go to Filter > Extract. A new interface will appear. Select the Edge Highlighter tool with an appropriate size, draw along the outline of your subject. It does not have to be very accurate.
Get the Fill tool to fill within the highlighted outline you drew earlier. Click on Preview button. Hit OK if you are satisfied else redo highlighting the edges.
Method 3 - Layer Mask:
Select the layer of the subject and click on Add Layer Mask. You will see a white box appear on the layer tab. Select Brush tool of an appropriate size and color #000000, start painting the areas outside of the subject. Things to note are, #000000 is to hide and #FFFFFF is to reveal details.
This method is very forgiving by toggling between these two colors.
Method 4 - Magic Wand Tool:
This is a very fast form of extraction provided the background is of similar colors. Select the Magic Wand tool on the left and click on any part of the background that you wish to remove.
You may try different values on the Tolerance. Once you selected the whole background, press Delete.
Method 5 - Lasso Tool:
This is similar to Pen tool except that no work path is created during the process.
Select Polygonal Lasso tool and start to point along the edges of the subject. Double-click on the left mouse button once you are ready to close the selection.
Select > Inverse. Press Delete.
More Tutorials: 
