Practical gifts may not seem that exciting, but a teacher will thank you for them. Especially in this time of budget cuts, teachers often spend a substantial amount of money on supplies for the classroom. Giving those items as gifts will likely be appreciated. Think of items like books for the classroom library, dry-erase markers, a supply of good pencils or even sticky notes.
Teachers get many trinkets like candles and coffee mugs, but a few years later, it's difficult to remember which specific child gave which gift. Worse yet, some of those things may even wind up being given away or sold at a yard sale. A gift the teacher will remember is one a child makes themselves. This is especially appropriate for elementary-age children. Think of a craft project like a picture frame or even a picture your child draws. Add your child's name or photo to the gift so the teacher always remembers who it is from.
Few teachers would turn their nose up at a plate of home-baked cookies. Again, this is a gift that shows how much your family cares. It takes a little effort, but doesn't require much money. If your child can help with the baking, that's even better. Think about adding a picture of the child stirring the dough or rolling out the cookies. This is a gift the teacher will truly treasure.
If you don't like the homemade route, consider purchasing gift cards for coffee or a favorite local restaurant. This kind of gift is often appreciated more than a candle or other tangible gift. It helps if your child is observant and can let you know whether the teacher often has coffee in the morning or talks about chocolate a lot. You will rarely go wrong with this kind of a gift.