Hi guys
I found this a very useful tool, that I am using it a lot in Blender. It lets me quickly edit the model. It is called Proportional Editing
And the other tool is mirror editing:
When moving vertices on one side of a mesh it mirrors it on the other side as well.
I could quickly edit this long sleeves
into this, with the help of these tools 
Hope you find them useful as well.
Best Regards