Step-by-step: Keep your balance
To get the “off balance” look, tilt the horizon line. Wide-angle lenses also help: they display more background than our eyes normally see. To achieve this, set vanishing points closer together than normal. At least one vertical vanishing point will strengthen the wide angle effect.
A loosely coloured background draws attention to the figures. If you decide that the figures are your focal point, then all choices should support that. Two more figures to help fill the scene, and add some narrative. The head waiter is calm, which highlights instability in the others.
I place a Multiply layer above the local colour layers to add some extra form. Once the character layers are flattened into a single layer, you can Transform>Warp the characters to tweak the gestures. Used sparingly, it adds extra life into an already well- developed pose.