There are plenty of great restaurants in Prague, but be warned that the customer is not always King in the Czech Republic. Prompt table service is not the norm, especially in less touristed areas, and it can be hard to get the attention of the waitstaff. Small tips are the standard - just round up to the next dollar and leave the change. In nicer restaurants, you should tip about 10% (15-20% is too much.) Water will cost money along with any bread/pretzels that are left on the table - even if you didn't ask for them!