how to write a theisis statement

Your thesis statement is no exception to your writing: it needs to be as clear as possible. By being as clear as possible in your thesis statement, you will make sure that your reader understands exactly what you mean.
The thesis statement should do more than merely announce the topic; it must reveal what position you will take in relation to that topic, how you plan to analyze/evaluate the subject or the issue. In short, instead of merely stating a general fact or resorting to a simplistic pro/con statement, you must decide what it is you have to say.

Anticipate the counterarguments. Once you have a working thesis, you should think about what might be said against it. This will help you to refine your thesis, and it will also make you think of the arguments that you’ll need to refute later on in your essay. (Every argument has a counterargument. If yours doesn’t, then it’s not an argument—it may be a fact, or an opinion, but it is not an argument.)
A good thesis has two parts. It should tell what you plan to argue, and it should “telegraph” how you plan to argue—that is, what particular support for your claim is going where in your essay.

“Solo European travel requires independence which, in the end, bolsters personal confidence.” This is much more specific and targeted. Now, you can hone in your research on solo travel through Europe, the need for independence, and its positive effect on personal confidence.
As you can see in the thesis statement examples below, you must be very specific, summarizing points that are about to be made in your paper, and supported by specific evidence. Generally, your thesis statement can be the last line of the first paragraph in your research paper or essay.

Your thesis statement might have several parts, but they should all add up to a coherent whole, and it should clearly relate to the rest of your paper. Make sure that the main points of your thesis statement appear in your section headings or topic sentences.
A good essay or research paper builds up to a central argument. Your reader wants to know what that argument is and how you will make it – your thesis statement should tell them in a sentence or two.

When composing a thesis, you must consider not only the format, but other qualities like length, position in the essay, and how strong the argument is.
Example of weak thesis:

References:

http://writingcenter.fas.harvard.edu/pages/developing-thesis
http://examples.yourdictionary.com/thesis-statement-examples.html
http://www.scribbr.com/academic-essay/thesis-statement/
http://www.easybib.com/guides/how-to-write-a-strong-thesis-statement/
http://content.nroc.org/DevelopmentalEnglish/unit09/Foundations/creating-a-thesis-and-an-outline-for-a-critical-analysis-essay.html