When to give thank you notes?

So college applications is once again upon us. As a high schooler, I need recommendations from teachers, and think its important to give a thank you note. My mom agrees, and bought $15 target gift cards to go with it. However, she told me to give it to them when I give them my recommendation information, because if I give it after they’re done it won’t have an effect. I just wanted to give thank you cards as a token of appreciation and think that my mom’s course of action might be misconstrued. So, if a student hands you information about her application and then gives you a thank you card, What’s your first reaction?