Hazards should be noted ahead of time. You should advise your moving people of damaged or very fragile furniture, weak or broken stairs, or impediments that may affect the move so that they can take extra care when around them.
Cleaning supplies, oils, liquid foods, paint and solvent containers should all be checked for a tight seal if you'd rather save and move them. In that case box them up, stuffing the boxes with a lot of bunched up paper, towels or cloths to absorb any drippage or spillage that might still occur. One good idea is to put one heavy-duty plastic trash bag into a second one and then line the box with this double layer to hold in any liquids that might spill. Bottles and cans of liquids should be stood upright in the box using packing paper bunched up between some to hold them upright. Never put ammonia and bleach bottles in the same box because the combination of those 2 particular household chemicals has been known to cause explosions! Place any boxes of liquids on the floor of the truck, not up in the load where spillage could damage your household goods underneath.
It is against the law to transport alcoholic beverage containers that have already been opened in any motor vehicle - even locked in the back of a truck - so definitely dispose of them!