Clinking glasses has become a common way of expressing your agreement with the sentiments shared during a toast, symbolically uniting the individuals who share in the occasion. It is generally considered bad manners to put your glass down before the toast is finished or to hold your glass without taking a sip at the end of the toast. However, if you prefer not to drink alcohol, it is perfectly acceptable to fill your flute with sparkling grape juice, or even water in order to participate in the toast.