The first thing to do is make sure your application is the best it can be - start writing your personal statement as early as you can, and spend time getting it right. There's lots of advice about writing your statement, including plans to follow and a short video guide on what to include, in the personal statement section.
Select your choices carefully, matching your skills and achievements to the typical entry requirements. Use Course Search to see the entry requirements and skills or experience required for each course.
When you're replying to your offers, think carefully about your insurance choice - it's really important that you choose a choice that you want to go to if you're not accepted at your firm choice. You don't have to have one - if you're not sure about any of your other choices once you have accepted a firm choice, you're not obliged to accept one as an insurance option. But if you do, make sure you're accepting it for the right reasons.