This is just a fun little exercise to test if a helical structure is either left- handed or right- handed.
Step 1. Make fists with both your hands , your thumbs must be outstretched of course and pointing straight up.
Step 2. Look at either your left/ right hand and picture a helix spiralling up in the direction of which the other four fingers are curled.
Now depending on which hand you were looking at you would notice that your right demonstrates a right handed helix and rotates in a counter-clockwise direction, while your left will rotate in a clock-wise direction and demonstrate a left handed helix.