best way to warm plates.

tacpot12

If you are boiling anything in a pan on a hob, pop the plate on top of the pan for a minute. Take it off and set it on a folded tea towel to dry the underside. 

JIL

Put the gravy on the plate first.

bob_a_builder

If your toaster is next to a wall, stand the plate(s) in the opening slot of the toaster leaning against the wall 
Turn on toaster  
Job done 

Slinky

I've never heard of damaging a microwave by heating plates in it before. I heat 2 Denby plates for 1 min 40 seconds. Have been doing it for years.

At Christmas when I needed the microwave for something else, I warmed my plates with a filled hot water bottle!

Ectophile

JIL said:

Put the gravy on the plate first.

That leaves you with food covered in cold gravy.

ouraggie

If oven is on I put them in the grill compartment. If I forget, I microwave them for 30 sec .
If oven not being used, I stand them upright on the radiator while food cooks on hob. 
If rad is not on, probably the plates are not stone cold so I just use thm straight from the cupboard.
 

Davesnave

In winter, on the wood burner for 30 seconds or so....