It depends really on several factors; if the date is romantic and you spend quite a long time with them getting to know them and feel a real connection between the two of you, then a kiss is appropriate. A kiss at the end of a date is optional, it isn’t expected and your date will probably be wondering the same thing. If the date was brief or you didn’t get a chance to get to discover much about them, then it might be best to wait until a future date before you lean in for a kiss. If there was no connection at all then a kiss is completely inappropriate, not to mention giving off mixed signals.