First. lets look at the reserved sign: This is a simple way to make sure that there is a good spot for your grandmother and other close family to sit. This is most commonly used when a buffet dinner is served. A simple sign is placed on the table to keep others from sitting at this table. It is important to make it very clear though who should sit there. Otherwise no one will sit there. You can place a list on the back of the reserved sign or have your planner assign someone to escort the appropriate guests to their table.
The second option is the seating chart. The seating chart is a one or two page list of which guests are seated at each table. This is often printed poster sized and place on an easel at the guest table. Each table then has a sign with the table name or number on it. Guests then sit at any place at the table that they like.
Third is the escort card. Guest find their name on a place card on the guest table and take the the place card to their assigned table and set it at their chosen seat.
The final option is the most formal (and the most work for the bride and groom). Guests find their name on a seating chart, and when they arrive at the assigned table they find their name on a place card at their assigned seat.If you decide to create a seating chart, be sure not to leave it to the last minute. Start making some choices before you get all of your responses back and just make final adjustments after all your guests have responded. It is best if you can give your designer at least a few days if you have just a seating chart and at least a week if you are doing escort cards.