Well, maybe this only works in the UK as we are pretty liberal about alcohol
In senior school my boys always took in a nice bottle of wine for favourite teachers. In addition my wife makes home made rum truffles and each teacher received a hand made pouch of rum truffles. We tried to select wines to match where they had been on vacation or that had names with links to their hobbies or interests. We never had a bottle refused. My youngest son had a lovely teacher who was a muslim and so my wife used no alcohol in her truffles and we bought her alcohol free sparkling fruit champagne.
My eldest lad who now works in IT had a lot of support from his music teacher who did not drink wine but drank beer. We used to spend a good few hours driving and walking around the wine cellars looking to put together a selection pack of 6 beers from micro breweries around the UK and Europe.
In junior school it was rum truffles plus a small bouquet of flowers (most teachers at these grades were women)
Really extra special teachers were invited home to dine with us, my wife is a great cook, and I would act as taxi driver so they could have some nice wines with each course including some Sautern with desert or one of my favourite Brown Bothers late bottled Muscat