I printed out reference pictures of Thor's armour and measured myself.
Then I drew out the templates for the different pieces of the armour on card stock.
Once the templates fit my frame perfectly then I used these templates to cut out the different piece of armour from the craft foam.
Then I hot glued the pieces together which creates the layed look needed for Thor's armour.
Tip: When using hot glue, flip a dust off can upside down and the spray will rapidly cool the hot glue saving you tons of time.
I used this method for all the pieces of the armour, the chest piece, gauntlets, and boots.