The following are some ideas about prizes that you should consider when creating a prize to be awarded to the winner of a draw.
The prize should be attractive enough that it will create a sense of anticipation among your customers that they might win the draw. For a restaurant this could be a gift certificate entitling the winner to dinner for two with a limit of $70 which would be sufficient to provide for an entree, dessert and a beverage for the winner and a guest.
For an automotive dealership the prize might be a detailing package or a free oil change or something similar.
For other businesses you might consider some sort of gift that your business can provide, or you could consider partnering with another business that is relatively close by where you purchase (at a discount) the gift product from the other business (giving full credit to the other business, of course) and present that as a prize for your draw(s). This cross-marketing technique has the advantage of raising awareness of the prize-giving business at the same time as presenting an appealing gift to your own customers.