It is a very natural situation and common phenomenon that people sometime find nothing to talk about or start a conversation with someone. You might be facing similar situation. In order to overcome this, first of all you have to be easy, comfortable, happy and calm.
Your conversation depends on few factors; like, with whom you want to speak? What way you want to speak? What is the occasion? How much is your acquaintance with him/her? What is the purpose of conversation? You may have many more situations.
There is some basic etiquette for the conversation. This must be borne into the mind. These are; in addition to calm and composed, you should bear smile on your face. You should be polite in conversation, a good listener and little bit witty.
You can start your conversation with very simple open ended questions.
Best way to start a conversation
Like, How are you?
How things are going on ?
From where you come from?
How did you come? How was the journey?
Where do you live at? Who are in your family?
Are you aware with the recent incident happened in our town?
What do you think about that?
What is your area of interest?
What did you like most?
Do you know so and so?
Have you seen recently released movie ?
Have you heard that Deep marginally missed the Olympic Medal, hard luck! So on so forth, you can start the conversation and take further lead to give your own opinion and/or have his/her statement/ reply.
You both will enjoy the conversation, if you find that the partner is taking interest in your conversation. You always keep in the mind that you have to speak only when he/she finishes the statement. Avoid interruption which may cause dissatisfaction to him/her and may gradually or suddenly stop the conversation.
Apart from this, there are few additional methods which you need to apply. You may tell some incident/story which may induce the other person to participate.
In the circumstances when you have a prefixed plan of meeting, in that situation you may make mental preparation of the topic which would like to talk about. This will help you a lot.
Last but not the least, always takes interest in the interest of your counterpart, as everybody wants to speak more about himself/herself or his/her ideas. If you are a good listener and have even few leading questions (open ended) you will never feel lack of topics to talk/speak about and your partner will always feel talking to you.