What is the importance of planning before working on your artwork?

Planning before working on your artwork is essential, for one, it prevents an artist from making stupidly simple mistakes which saves up on time. Similarly, planning lessens the possibility of wasting resources since a proper arranging of you efforts gives you the ability to progress evenly.  Instead of rushed work which causes unnecessary usage of supplies.  Likewise, planning ahead enables one to be able to practice or repeat a piece enough to be able to possibly perfect it. Also, when you plan out your artwork, there is a better chance of you sticking to the theme that your were given. As oppose to just winging it and getting lost somewhere in the middle and not meeting your objectives.