Homemade teacher gifts tell a teacher that they are appreciated. Anyone can go buy a gift. It is easy to buy a gift card. A gift that is made will be remembered and if that teacher made an impression, it should be memorable.
Group or Class Gifts
One of the best ways to make something special is to involved the entire class. This past year my wife was one of two room moms at my daughter's kindergarten class. At the end of the year they took all the money left over (less than $200) and made a scrapbook for the teacher and included some gift cards.
The big part was the contents. They had each child write a sentence about why the teacher meant so much to them and then draw a picture. Interlaced between the drawings were the gift cards and a number of pictures from class events during the year.
Needless to say a number of tears were shed because of what each child said and did to show their appreciation. Now of course it is much easier to get kindergarten kids to do this than older kids but the process is the same.
Other Group Gifts
Other ideas include things that teachers would not ordinarily buy for themselves. Pooling funds always makes for a nicer gift. The important part is to put something personal from each person in the class. It can be private but the personal touch is what makes the difference. Other than scrapbooks it can be songs, something the class does together like record a video or tape a message. Make it personal.
Individual Gifts
Same thing applies with the group gifts, make it personal. Pictures, mementos, personalized items are all good options for the individual. The homemade part comes from what you put into it yourself. It does not have to be expensive but it does have to be personal.