All essays that involve the development of an argument require a thesis: the point you are arguing. While the topic is your subject, the thesis defines your position on that subject. Your essay will take a position and will provide convincing evidence to support that view. It is important to develop a working thesis early because it will help direct your thoughts and research; of course your thesis may change as your reading and writing progresses and you begin to incorporate new information.
Once you have chosen your topic, you can begin to formulate your thesis by thinking closely about it, doing some exploratory reading, or drawing from lectures or conversations with classmates and friends. One way to develop a thesis is to ask yourself questions about the topic and to focus on a central issue or problem, which the topic raises. Your answer to this question will be your thesis.

Brainstorming
If you are having trouble developing a thesis, try brainstorming. You can brainstorm verbally with other people, or work alone, writing all your ideas on paper. The important thing about brainstorming is not to edit your thoughts. Write down everything, which occurs to you about the topic, no matter how irrelevant or bizarre.

The next stage is to make connections between your ideas, and to group them into sub-topics, expanding those that you can explore in more detail. Then see if you can put the groups into some kind of logical order, discarding those that do turn out to be irrelevant or bizarre. In most cases you will find that you have the beginning of an essay - something that implies a basic point of view you can explore further and refine into a fully developed argument.

There are several good books on using the brainstorming process to generate ideas for writing, including Tony Buzan's 'Use Both Sides of Your Brain' and Gabrielle Lusser Rico's 'Writing the Natural Way'. If you are still unsure about the topic, you should consult your instructor after you have done some thinking about the topic on your own.

To further, elaborate on thesis keep in mind these goals, which will help you even more in writing a thesis for your essay.

1. Building a strong thesis
   
   Your thesis should have a strong stand, conclude your thesis with strong statements.
   
   For example
   
   A vague thesis statement
   
   There are some positive and negative aspects to the All-slim diet plan
   
   Strong thesis statement
   
   Because all-slim diet plans take into account diet pills and no amount of carbohydrate all day which can result in harming a persons body if he doesn't follow his doctors advice and start this diet without his recommendation his weight will be lost but in long process his health will suffer.
   
   
2. Give your thesis a justification
   
   Your thesis should not be a simple sentence, make it in a form that discussion arises from it which is duly justified by proper reasoning.
   
   
3. A strong thesis follows only one main idea
   
   Never confuse a reader given him more than one idea, try to focus your thesis statement on one main idea and work on it the whole way.
   
   
4. Make your thesis specific
   
   Try to make your thesis specific and to the point, don’t let your point stray in the the opposite direction this will help in making your essay manageable.