Thank you note and gift card, $25, to 3 people: their Counselor, who wrote a recommendation on the common app, as well as the 2 teachers who wrote individual letters of recommendations

Hello,

Since this is our first rodeo (first DC), and we both went to HS eons ago in a different country, we are wondering about the general custom in this area w.r.t. gifts to teachers from graduating seniors. Any pointers appreciated!