Sketching Technique

so basically , hatching technique is you consists of lines from one direction
cross hatching consists of crossing lines
scribbling is just scribble and you gradually shape the object
while stippling.. well..you need to break your hand hahahahaha you need to make A HELL LOT of dots to form the shape of your object
btw ,I did the stippling in the library :) thank God they didn't kick me out
okay here is the pictures of each techniques
hope it helps ;)