I have that problem too. I usually narrow it down to two or three options and ask the server/cashier what I want. About 80% of the time I go with whatever s/he

I have that problem too. I usually narrow it down to two or three options and ask the server/cashier what I want. About 80% of the time I go with whatever s/he says; other times, simply hearing his/her recommendation makes me realize what my actual preference is.