Whatever command you choose, always keep the command the same. Be consistent, always make sure what you have instructed has been done (make sure it has followed through and actually sat if you have asked it to sit). Always think before you command i.e. if you don’t think the dog will achieve that command or you can’t manufacture the success then don’t ask it. Dogs hate to fail and the more a command doesn’t work the harder it will be to train into the animal.
Work together as a household and make sure you’re all treating your pet the same and all using the same commands and implementing the same rules. This will make it much easier for the dog to learn and understand his / her place within your family.