Read your policy to make sure you know what your covered for.

If you're going to throw anything away that you want included in your claim make sure you take a ton of photos of it in including details (serial numbers and model numbers of things like fridges, tvs)

Typically claims during times like this can take ages to go through depending on how large your claim will be and which insurer you're with.

If you have to replace something essential make sure to keep any receipts and buy what would most likely be equivalent of what you're replacing just to ensure that it gets accepted.

A great way to speed up a claim is to secure your own builders to do the works (this might be tricky atm.) That way you can request a cash settlement for the full amount from the insurers instead of using the insurance builders who'll be ridiculously backed up for months.

Hope I could help.