I honestly don't even tell dogs 'No'. Not sternly, with an intent to shock, scare, intimidate, or else wise. I do like a punishment marker for when I am using negative punishment (taking a fun thing away).
For instance, if I get to a house and the dog is going bonkers jumping up and won't ignore an 'off' on the second time, I just say 'too bad', turn on my heel and leave. This gets them thinking 'well dang, now I'm not going on my walk!'. I sit on the stoop and browse DF and try again from the top a minute later. The dogs that I walk learn quickly that I am a very predictable person, and that I can do this all day long if they would like. But 100% of the time, they'd rather cut the crap and go on their walk already!!!
The only instance where a time out works as far as I am concerned is if the dog is in a high-arousal mode and simply cannot calm down for long enough to think straight. In this case, you're removing them to a calm, low-distraction zone so that they can take a breather and cool their jets.
When a dog is doing something naughty, to me this is an indicator of any combination of three things:
a) They need to know what they should be doing. All four paws not he floor, chewing on their rawhide instead of the couch, coming to me when they see a dog/person they want to greet, etc. This is achieved by training and capturing desired behaviours.
b) They need something better to do! A walk, training session or play to burn off excess energy, a toy to chase instead of the cat, something tasty that's acceptable for them to chew, or a puzzle toy to get food out of.
c) They need to be capable of choosing the desired behaviour. A prey-driven dog needs LAT/BAT training to enable them to ignore squirrels. A dog with separation anxiety needs counterconditioning to remain sane without eating the bed. An impulsive dog needs impulse control to learn to say 'no' to the sandwich you dropped.
If the dog is doing something like chasing the cats, I think that a sufficient way of dealing if they just can't ignore a 'leave-it' is to tell them 'You're coming with me, how d'you like that?!' and tether them to you
That way they put it together fast that if they want free run of the house/park/yard/etc... they can't be chasing cats, dogs or people!!! Of course, this sort of training doesn't work alone: you have to be confident that the dog can maintain some control of their chase instinct, by methods such as counter-conditioning and desensitization. And they have to be rewarded for proper behaviour, for as many weeks/months/years as you feel necessary.
My advice? Buy a good waist-clip treat bag that is handy for you to use. Wash the dog bowl and put it away in the cupboard. Good behaviour is Sophie's new food bowl now. Put a day's worth of food in a bag on the counter and top your pouch off as necessary. When you notice her doing things you want her to do, even if its as simple as lying around not bugging the cats, that is when you feed her. Any surplus food can be put into puzzle toys to keep her further occupied.