For the main piece use these settings to make it watertight:

• 5 perimeters 
• 5 bottom layers
• 5 top layers
• Iron the bottom hole
• 100% infill
• 1.1 extruder multiplier 
• 30 mm/sec speed
• nozzle temperature at max allowed for that filament 

Print on the given orientation, no supports required.

Link to the ice tong shown on the photos https://www.thingiverse.com/thing:4820362