Order matters, and almost every guide gets it backwards
The order
Ground floor first, furthest from the boiler, then work upward and inward. Doing it the other way means doing it twice.
Heating off
Cold system, pump off. Bleeding a hot system moves air around rather than out and can scald you doing it.
Afterwards
Check the boiler pressure and top up if it has dropped below one bar. Bleeding always lowers it and this is the step people forget.
