Landings have priority over take-offs.
'Dead stick' landings have priority over landings. (And any other called 'low' manoeuver)
Only taxi onto the runway when is clear to do so..

And above all else, curtesy rules. Watch teh other pilots, and see what they are doing. At any decent club, the pilots should be calling out their intentions.. Fly / taxi accordingly, just call out your intentions, so people know you're on the runway..