Going to renew visa online. Experience?

So, going to renew the visa online. Though I’ll give it a go
People that has done it says it not the best.

So, to be proactive.
Is there anything I should keep in mind.
For example, I read that all documents should be in one file.

Is there something that’s really cryptic? Or just… unclear whilst doing the process?

Thank you in advance and have a good day.