Guitar strings have always been a complete pain for musicians. For some one set will last for ever but for others you can't go a gig without having to change your strings. There are things you can do to make sure you don't have to change strings as often, like pick up a set of these Elixir 10-46 12 string strings.
Elixir produce strings with different types of coating but their most popular by far is their Nanoweb line. This coating is so thin you will barely notice it which helps with playability and making sure you still have the same bright new string sound. Plus the strings last much longer with this coating thanks to their anti rust nature. Normally you can get between 3 to 5 times as much play time when compared to non coated strings.
Non coated strings famously make a lot of noise as you move your fingers over them. This squeak has become a pain for all guitarists who want to achieve the perfect performance with no extra sounds. The nanoweb coating helps fix this issue by smoothing the surface of the string reducing all kinds of extra noise.