dogs aren't much different to horses to train when using tone.
when you discipline, take the town downwards but do not yell or raise the pitch, this is a playful tone.
when you say no, short and sharp but without raising voice and if need to reprimand for something serious add a growl to the tone.
when you are playing, if you want him to drop a toy, use one word commands... 'saint, drop' (saint, playful and light, drop.. short sharp lowered tone but no growl)
sit.. saint, sit... same tone as above...
get him to listen.. practice with one or two things at a time.. use treats for good behaviour, he will learn faster with praise.. when you do praise him use the playful tone.
good boy saint.. light, slightly higher in pitch and repeat it with pats and then really soft so that he realises the difference.
when you want to teach him walking on lead etc.. same rule applies but you can incorporate clicking the fingers as you use your (short sharp yet soft)- sit,(at your feet ready for a further command) 'stand' or up is light but sharp, - (ready to do go for a walk or something else and the next command) wait, drawn out slightly but firm without being playful no growl unless having to repeat (when feeding, opening doors, putting lead on, anything he should wait for) all these commands are easy to teach when you use the right way .
he will learn the differences :)
be consisitent and if you have to write what you are teaching him.. do it :) good luck.