You don't have to write all the Less code yourself as it is reusable and portable. Mixins and snippets of Less code can be found on the Web and (re)used in your projects. Search for Less mixin background gradients and you will get many useful hits. Try to find code that offers support for browsers and meets your requirements. If you have any doubts about the browser support of a mixin, consider asking questions on Stackoverflow.com (http://www.stackoverflow.com/). Always show your code and what you have done; don't just ask for a solution. Also, other questions regarding Less can be asked on Stackoverflow.com.
Integration of code snippets or even complete namespaces will make the testing of your code more important.