Be clear. There is nothing worse than an open ended thesis. The standpoint needs to be extremely straightforward, leaving no room for question or confusion. Pick a side. You should either be for or against the topic of the thesis. A position should be mentally established before the thesis has even been written. Otherwise, it will not make sense and may come off as unsubstantial. Without a firm position, it will be a summary instead of a thesis. Do not make this mistake, it makes all the difference.
Be bold. Form an opinion in the thesis that the reader will not necessarily concur with upon picking up the paper. This will grab interest. Don't just go on a rant about something completely negative. Your job is to state your opinion, and convince readers to agree with the idea by the time they are done reading it. If successful, not only will you get a good grade, but you will create a lasting impression with the audience.
Present original ideas. Provide readers with something they haven't read before. This will make the paper more interesting and memorable. Provide personal experiences and interviews to show that you have done plenty of research. Demonstrate that you have learned something. If that's the case, readers are likely to learn as well, which is a good strategy. A good thesis is one that readers will not want to put down. Be insightful to keep your audience interested. Don't be repetitive either. If the temptation to reiterate a sentence or idea comes up, omit the idea altogether. Don't give the audience the idea that ideas for the paper were limited.
Uncover nuances. Don't procrastinate if the desired result is a great thesis. The key is to spend several days working on it to think about what will be incorporated. Delve into your own thoughts in between writing sessions and explore every possibly. Once the work is completed, proofread it again and again. Improvements can usually be incorporated. Don't let that careless spelling error or tense change bring down the credibility of an entire paper.