2) Sew on the machine yourself. 
Sew on the machine yourself. If they won't let you touch the machine, go elsewhere.

3) Ask the salesperson what machine they own.
If they own another brand, other than what they sell, what does that tell you?

4) Ask about classes and "Clubs".
If they don't have any, don't expect much support.

5) Ask who owns the store.
Locally owned and operated stores support the local community. An "Independent Authorized Dealer" has roots in the community.

6) Do not make your decision based on price.
Price is a factor in any decision but one should consider the quality and quantity of service to be included with the purchase.

7) Know the facts about buying over the internet.
As an educated consumer you should be aware that the manufacturer's warranties only apply when you purchase your machine from an “Authorized Dealer”. Most reputable sewing machine manufacturers have restrictions pertaining to the sale of their products via the internet and do not provide warranty. The money you may save at the time of purchase could well be out weighed by what you may spend later on. Remember time is also money.