I mix and match my technique depending on the dog at hand.
My older dog was trained in the past (by my father) with a very heavy hand. So if you roar and rage, she becomes meek and in the past used to fear pee. I have worked her out of that, but there are times, where she KNOWS what I'm telling her to do, I have asked nicely, and there's a time and place to bring in the big guns, and in a big booming voice I will let her know. Works wonders for her.
For my new puppy, she is very forgiving, learns quickly, but does sometimes get way too into something, and ignoring doesn't work for her. She bites down on me too hard in play or excitement (I teach bite inhibition, where the moment they feel skin they do not bite, but only mouth, since I want to be able to mess around with and play with my dog's mouths, not have them fear my hand coming near it because of demanding no mouth contact at all), and I have quickly jerked my hand away and gave her a wack. It knocked her out of her overly excited state, she stood there for a moment, and then I encouraged her back to play. She's a very happy and flexible puppy, and took it all in stride, and since that time, she's been a lot more careful about the way she mouths me. Not out of fear, but out of "oh... that ended play time for a while". But had I just gotten up, or moved out of the way, or ignored her, like I have done before... she still sees that as a game. Not game over. So I used what worked with her.
I don't beat my animals, 99% of everything I do is verbal or using hand signals. However, I demand respect from my animals. I give puppies leeway, I am gentle and slow when they are learning, but once they know, and push the boundaries of respect, I will correct them.
For example... I have a horse. She is usually awesome at feeding time. Knows to give me space and wait until I have put her food away, and she's not allowed to rush it or me. We established this from the start. A new horse came in, started stealing some of her food (I quickly adjusted after the first day and they both get plenty), but a few days later, she became very pushy. Trying to grab hay out of my hands, pushing me over. She's 1400 lbs or so. I'm about 15% of her size. If she pushes me, it's dangerous. So while I am all for positive reinforcement training, I have used a whip on her to remind her that my space is my space, and I demand respect.
I have not used a whip on any dog (soft bouncing on their back in play doesn't count). Because they are not 1400 lbs. My life isn't in danger if they push me. However, if they are not listening to me, stuck on something, I will correct them, and physically. It's not abusing them... it's reminding them.
I'm firm. I'm not mean. I'm positive and upbeat... but if my animal is being rude or disrespectful, they will know.
Also, I adhere to the NILIF concept. It's not pack leader, it's not crazy "I rule the world"... it's making sure they know that what they want, they have to work for. And sometimes the only "work" that they do is being respectful and having manners.