My girls do their own cards. DD3 in kinder had DD1 help her out. They give cards to their friends. They give them to the teachers that have a connection with. I follow their lead with gifts as well - the teachers they are close to I usually let them do a small token gift.
If I feel the need to say a special thank you, I simply do it by writing something lovely in a card.
I'm actually thinking about dropping in a box of chocolates to the office ladies tomorrow, just as a thank for all the icepacks, bandaids, and looking after of tummy aches etc with my girls
Not to mention all the other work they do in the school.
DD3 did ALL her teachers, with gifts to the 2 class teachers (4day/1day).
DD2 only wanted to give to her 2 classroom teachers (3day/2days). As it happens, the two girls had the same teacher, so I did one gift, but they did their own cards.
DD1 did a gift for her teacher, and cards for a couple of the teachers.
In the past, we've done small gifts for the librarian, for the band teachers. DD1 even gave a card to principal the first couple of years. Last year, DD1 didn't want to even give her class teacher a card let alone a gift. Instead, she wanted to give a gift to one of the kinder teachers who had been mentoring her a lot during the year. I talked her into doing a card for her teacher, but was quite happy to follow her lead with the gift.