You follow a series of steps.
Step 1. Draw the structure of hexane.
Step 2. Convert it to a wedge-dash structure at ##”C-2″## and ##”C-3″##.
Step 3. Identify the groups on ##”C-2″## and ##”C-3″##.
The main chain of hexane is the horizontal zig-zag line of carbon atoms.
##”C-1″## is on the left.
The groups on ##”C-2″## are ##”H”##, ##”H”##, and ##”CH”_3##.
Those on ##”C-3″## are ##”H”##, ##”H”##, and ##”CH”_3″CH”_2″CH”_2##.
Step 4. Draw a template for a Newman projection.
Step 5. Attach the groups to the carbons of your template.
View the molecule from the upper left.
The groups on ##”C-2″## go on the front carbon atom. Put the ##”CH”_3## group on the bottom. The two ##”H”## atoms go on the other bonds.
The groups on ##”C-3″## go on the back carbon. The bulky ##”CH”_3″CH”_2″CH”_2## group goes on the top, and the two ##”H”## atoms go on the other bonds.
This is the most stable conformer, because it has the bulky methyl and propyl groups anti to each other.