I agree with above. Some veggies break down easier and smoother than others . A little liquid can make all the difference in the world. A lot of times, I also transfer whatever I am using the immersion blender for into a container or pot that is taller and thinner, therefore, making sure the the blade is always submerged in the puree. Sometimes if its a large wide pot, the blades aren't completely submerges, so nothing gets pureed properly, and stuff splatters all over. Sometimes I'll just tip the pot a little to create a certain depth on one side of the pot.
***OBVIOUS BUT CRITICAL COMMENT***
WHEN IT GETS CLOGGED, BE SURE TO UNPLUG IT BEFORE CLEANING OUT THE VEGGIES FROM THE BLADE.
Im sure you figured this one out, but could get ugly