You could just start with making a 3x3x5 cuboid..
Just need a super 3x3x3 cube and a couple of cubies for extention..
Here are the tutorial links,,
viewtopic.php?f=15&t=20012&hilit=lazy+man+3x3x5or maybe this one which is more simple,,
viewtopic.php?f=15&t=23821&hilit=lazy+man+3x3x5Maulana