Blenders
Jug blenders and personal cups show up in the same category, and they fail in different ways.
A jug blender makes a litre of soup or a thick smoothie. Ice needs a jar and a blade that the manual allows to take ice. A cracked jar is usually from ice in a jug that was only rated for soft fruit, or from the jug being dropped, not from age alone.
Thick mixtures climb the blade and leave a dry well in the middle. A tamper, on the models that have one, pushes food back down while the lid stays on. Stopping to stir with a spoon works too, once the blades have stopped.
Personal cups blend one serving. The blade assembly screws onto the cup. If the seal is wet, or the thread is crossed, the cup leaks the moment you turn it upright. Dry the seal, then twist until it seats. Do not store the cup with the blade on and the smoothie still inside. The seal takes the smell and the thread sticks.
Hot soup in a sealed personal cup builds pressure. Vent it. The jug, with the lid cap removed, is the safer vessel for anything that is still steaming.
Juice rather than a puree belongs under juicers. A wand in a saucepan is the immersion blender.