Schmoozing, buttering up, brown nosing, call it what you will, but being extra nice to your children's teachers is nothing but a good thing. First of all, they deserve it -- can you imagine putting up with 20-plus kids your own kid's age all day, every day? Me neither.
Also, you just never know when you're going to need their help. Be it with extra attention to a problem your child is having or to maybe get a ruling in your favor when it comes down to a split decision as to if you made the tardy bell or not, it's always good to have the teacher like you and your child as much as possible.
That doesn't have to mean being obnoxious (no one wants to be THAT parent) or sending in elaborate gifts, but there are some little things you can do throughout the year to build a better relationship with your children's teachers.