I gave presents to most of my teachers.
English Extension teacher was overseas, so he missed out.
For my Business, Maths, PDHPE and English teachers, I bought each a box of chocolates with a card attached to it expressing how I much I appreaciated their help. Great thing was that I handed them out at the graduation dinner (great night, so a great way to cap it off [2nd last day of school]). My PE teacher wasn't there, so I hate his chocolates.
For my legal teacher and mentor, i bought a box of perfume (5 Calvin Klein bottles, travel pack or something) and gave it to her on the last day of school after our presentation.
I think it is better handing presents while you are still at school, the gloss is not there when you hand it after your exams.