Guide to write application for Unmarried Partner Visa?

Hi everyone!

I’m going to be applying for an unmarried partner visa within the UK in the next few months. Reading a lot of forums I’ve concluded that my application is pretty straightforward and I don’t need a solicitor’s help to compile my application. However I was wondering if there’s a detailed guide or template i can refer to start readying my application? It seems a bit overwhelming with so much information to include, and I’m also confused about how much is too much information, what and how many photos to include etc. I just want something to start off with at least.