Mixing The Shapes

Who says you have to pick one table type and stick to it?  It's common for guests to sit at rounds, while the bridal party is on display at a rectangular table.  You can opt to have banquet tables, rounds or squares for your guest seating too.

PROS -
*  The mixed look instantly adds texture to your space and doesn't increase costs much, if at all.
*  You don't need to assign seating: guests can choose tables that work best for their group - a couple who doesn't know anyone else can go for a small round and your coworkers can sit at a large table.
*  If your venue is small but your guest list is large, a custom seating plan is the way to go.  You can fit small tables into nooks or corners and line long walls with banquet tables.

CONS -
*  Unless you have a great eye, you'll probably need to enlist a pro to help with the floor plan so the reception looks stylish, not messy.
*  If you offer small tables that seat four or fewer people, you may need to hire more servers or choose to have food stations or a buffet.
*  The more kinds of tables and linens you have to rent, the more likely it is that there will be a mistake or miscommunication.