6) Beware of baked goods. I know homemade goodies seem like a good idea; thoughtful and lots of work can go into them. Having said that, I know several people who will not eat food that came out of kitchens they are unfamiliar with. Or people are just picky eaters. Baking for your teachers might not be a good use of your time. About half the teachers I knew happily ate goodies brought in by the kids; the other half gave them away or threw them away. (Go ahead, gasp in horror.) I'm just saying, do you want to put the time in if someone's not going to eat it? Now if you've given your teacher baked goods in the past and they have come back to you raving about your cookies/cake/brownies/bread/pie and asking for your recipe? You may commence baking.
7) Gifts the the whole class worked together on can be nice if you have an uber-parent to do all the organizing. It can either be one big item that the kids helped personalized (a friend of mine received a rocking chair from her class one year, decorated with the kids' thumb prints), or a collection of letters or drawing from each child, bound together in a little scrapbook. I think these kinds of gifts do require a little better knowledge of the teacher though. . .
8) Classroom supplies can also be a tricky area. If you know that the teacher has been buying items with personal money, than go for it. However, depending on your school, a lot of that might be provided already and not actually be coming from the teacher. Stickers or stamps are nice little gifts for most elementary classrooms.
Some of you are probably thinking, "Teacher gifts? Don't we pay them?" Well I will not go into that debate here, but the truth is you don't have to give teachers gifts at the end of the year, or at holiday time. You also don't have to tip the person who cuts your hair. It's a personal decision. Each school culture is a little different this way, and if you aren't sure (and you care) about what is typically done, ask another parent.
An end-of-the-year or holiday gift is just a way to let your child's teacher know you appreciate the fact that she (or he) spends a huge part of each day caring for your child, worrying about your child, and generally working her butt off to provide twenty or more kids with a safe and successful educational experience!
Having said that, a genuine thank you from you, your child, or both of you is just as nice as any other gift. Everyone likes to be acknowledged for a job well-done. If you appreciate the things your child's teacher has done throughout the year, just tell her. It's nice if you tell her principal/supervisor, too. I have saved all the thoughtful notes I've received from parents and children. When I was still teaching it was great to have a box of them to pull out when I was having a bad day.