I've volunteered to TO a tournament at my LGS this Sunday.

We don't have exact numbers as yet and we're expecting a few walk-ups - so the store owner has asked if I would step in to make up the numbers in the event that we get an odd number of players turn up.

I'm mostly fine with this but I'm wondering how best to approach this.

On the one hand I don't really want to be "That TO" - put on my game face and bring my most competitive list, but on the other hand I don't feel it would be fair on the other players if I were to relax my normally competitive mindset and gift wins to my opponents.

Is there a middle way or should I just approach this like I would any other tournament?

No reason not to approach like any other. But if you do well I would pass your TO prizes down.

I'd play like normal, but if you feel conflicted make sure they know you aren't going to take a prize no matter how well you place.

Just announce a backup TO who can make calls for your games.

Take whatever you feel like - go competitive, or take something you'd like to try and think would be fun.

Personally in this situation rather than going all-in with my one of my favourite builds, I'd try my hand at a list I feel could be good, but haven't used much, just to get some serious competitive experience with it.

If you're forgoing the prizes, you may as well treat it as a learning experience!

I play in most of the casual tournaments I run. I try to have 2 back-up TO's for answering questions or settling disputes. I've never had an issue playing as the TO (other than occasionally having to walk away from my game). You can play a very competitive list, but make sure you're flying casual (that is good advice anyway). The exception is premiere events. It is really best if you do not play in those. (Store Championships and above).

Just announce a backup TO who can make calls for your games.

Yeah I forgot that. It's vital IMO to have someone else be the judge for your games.

If you're going to accept the TO prize support, then just play the bye round. If you forgo the TO prize support and add it into the prize pool, announce a backup TO and play competitively! Just be sure to announce all of this ahead of time and you'll be fine. Set the expectations before playing for said prizes.

I've only played in ONE tourney where the TO didn't play - no problems! I plan to TO at my local store(s) and I will be playing as well.

Play a squad that you don't need to think about. Since you could be called away from your game, you won't want a brain-burner of a list that you have to come back to the table and spend any time thinking about what to do.

As others said, have second and third judges for your games. You might end up playing the second judge.