grammar - How to decide whether to use 'that' or 'which'?

I understand the principle behind choosing either 'that' or 'which' but I still find myself struggling to know in certain situations whether to use it or not. For example, "Here is a link to the article, which can be found on the Environment section of the website". Would it be that or which? I would use assume 'which'.

Do any of you have tips/strategies for knowing when to use 'that' or 'which' when writing a sentence?

Thanks