Oh yes,,,, no petrol in tank is MUST..even if your machine is going to be unused for weeks, it is still good habit to learn not to leave petrol to go 'off'. And I always aim to use 'fresh' mix or 'fresh'ish' of fuel when filling up for the job..and there is no point to fill up the tank full if one is only going to do 'so much' work at the time...saves emptying the tank if it is not all used up.
And the blades..get rid of soil and if you give spray of WD40 or similar maintenance spray..that will keep rust away or stops it developing any further.
Other than that, there is no much else to do...just keeping it in 'dry' place over winter. That is recipe that has been keeping my old machine going on for years and it keeps starting up without any major trouble in a spring again