From my experience attending and watching the inner workings of running a tournament there are a few things I've noticed:
Sign Ups:
If you have a medium sized tourney (like 30-40) make sure you allow enough time for sign ups. At the biweeklies here, sign-ups last a pretty long amount of time. While it is important to have a schedule, you shouldn't force them to be short so people who are playing friendlies all scramble up at once to sign up. Also, make sure to allow time to get the bracket set up properly and everything seeded correctly. For smaller tournaments (less then 20 people) you don't need as much time to sign up, because you can probably tell one everyone has signed up. And if you notice someone hasn't, it's easier to specifically ask them about it.
Calling matchups:
The speed you call the matchups at controls the pace of the tournament for the most part (well, in combination with people reporting matchups). I suggest when calling the first round of a tournament, to get everyone off of the TVs. This makes the room quieter, and allows you to assign matches to each TV easier. I suggest calling matches like this "SuperRad vs Joe Blow on that TV" *point clearly to TV*. That way you don't have to rely on people speaking up. If you notice after calling all the matches there isn't two people at the TV, recall the names to make sure you catch who it is. For matches after that, you will probably need to make sure to get eye contact with the person playing the match and direct them to TV and point out who they are playing.
Friendlies:
You don't want to stop friendlies completely, but for the first few rounds of your tournament you are probably going to want to keep your cubes friendly free. People that go two and out will probably be left spectating for a round or two, but that's life. It's important to not be afraid to tell people to wait on friendlies or flat out kick them off the TV.
Respect:
Respect is earned, and the best way I've seen to earn it is to just be a human being. Talk to people, make jokes, etc. If you are an ******* to people, people wont want to deal with you. Like neal said, after someone loses just throwing them a "Better luck next time" or something similar can make someone feel better. This is just a general human thing, not specific to tournament running or even smash. Also, try to not to be timid, especially as a TO. If you don't want to have to yell, or do things that people wont like, organizing a tournament is not for you. This doesn't mean you have to be a drill sergeant, but if you are the kind of person that doesn't tell restaurants they made your order wrong, you probably aren't cut out for it.
Don't be afraid to ask:
odds are that at your tournament there will be people that know more about smash rules and general tournament organization there. I see questions about counterpicking/stage selection come up all the time at tournaments. If someone asks you and you don't know, find someone who does.
this was longer then i intended. eh, whatevzzz