Around the touristic places there use to be people (usually gypsis) looking for tourist to read the hand or tell them any other story with the aim only of asking you for money.
As everywhere, just ignore them or simply, don´t talk to them.
Unique Suggestions: This people don´t mind if you understand Spanish or not. The simply talk as if you could understand.
Fun Alternatives: Don´t accept any present. Of course, it´s not a present and they will ask you for money.
Be weary of people dressed as gypsies on the streets. Some of them will give you a flower or these leaves (some will actually force you to take it), and then they will demand money. Also, they might talk to you or offer you a service, while one of their friends will come behind you and open your backpack and take your stuff... (advice is based on a horror story heard in a hostel)
Around the Cathedral, gypsies will give you rosemary (to be lucky), or will read your hand, of course they ask you for money, if you are not superstitious, do not talk to them, it is the only way they do not disturb.
There are many pick pockets active in the old town. Picture: statue of El Cid on a busy road in Sevilla.