Confused about ‘practise’ and ‘practice’?

Ever get confused whether to write ‘practise’ or ‘practice’?
Put simply, ‘practise’ is the verb and ‘practice’ is the noun. If you think of improving your guitar-playing then ‘practicing’ would look really odd and your brain would want to make it a hard ‘c’. You would write ‘practising’, which means you ‘practise’ on the guitar.
If you think of your GP practice as a physical thing then you’ll remember that with a ‘c’ it’s a noun.
We all know that practice makes perfect so you should practise all the time!! (Maybe the Americans have a point).