Paddling for a wave
It sounds incredibly obvious but look where you're going!
Many surfers, especially learners become so engrossed by the approaching waves, that they paddle into them whilst looking over their shoulder.
This is incredibly dangerous as you are likely to run someone in front of you over at close quarters, leaving little time to avoid a collision.
A quick glances over your shoulder before catching a wave is all that's required.
If a surfer is paddling back out and it's going to be a close call between running them over or making a take off, then it's better to not risk injuring someone.
This is a judgement call so know your own limits.
Sometimes a surfer paddling back out, will give you the nod indicating to you that they are happy for you to attempt it.
Other times they will scream "No!" at the top of their lungs, indicating that they doubt your ability...
It's no laughing matter being run over by a surfboard. It can damage surfboards and lead to serious injury- severed arteries, blinding etc, so think carefully before committing to a wave and analyse the situation - is it worth it?
Don't let go
Never let your board go. If you must - make sure you hold onto the 'rail saver' section of your leash (it's made of material) to prevent the board from hitting someone.
You may find that you've already committed to a wave that someone else is already on.
If this happens, don't just jump off and let your board slide over the falls i.e. down the wave face as you are likely to hit the other surfer with your abandoned board as they fly past.
If you have to jump off last minute - grab the leash nearest the tail of your board and yank it back towards you as pull away from the wave.
Be careful that the board doesn't fly back at you though. It's always best to look away or protect your head with your other hand if this happens.