Raising up and training of a familiy-dog 

Many books had been written about dogs training - each dog is an individual and should be taken as an indivudal accordingly. Yet there are some basic rules for dogs training, which are - more, or less - applicable for each dog owner.

One rule you should always consider : 
patience - patience - and patience again ! 

Due to own experiences regarding owning-dogs and dog-training I give some advices, which might be useful, but pls. bear in mind: each dog may react different in a determined situation and each still so good advice can fail. You must find out, whereupon your dog reacts especially positive.

1. exercising shall take place moderate but regularly and best begin already at puppy age. 
Motivating your dog - praise, stroking, remuneration etc. and - if necessary - punish "dosed ", according to the type of elapsing.
Senseless cudgeling and other uncontrolled reactions are strict to refuse. If necessary, a lighter flip, or shaking in the neck, prohibition- words, harder tone etc.

2. exercising with a normal necklace (e.g.leather, nylon etc., maximal chain-collare without train); prick-collar belong to the rigorous - training - and should only be applied well-dosed, with expert's knowledge, and is always to see as a transitional instructional measure- not as a duration-necklace, as unfortunably very often seen. If those necklace is too often used, there is a danger, that the dog gets accustomed to this"rigorous measures "and you haven't much opportunities left. So always for punishing start with the " lowest" level ; much more important is consequence, directly forbid something, set clear boarders - then need you will not need any rigorous-measures (a very dominant dog might be the exception of the rule).

Meanwhile we know that the Leonberger is rather sensitive to all the neck-pulling and shaking (esp. with the wrong necklace) and we use a harness till the dog is grown (as well this is recommended for older dogs as it may prevent any damage of neck and spine). The best leader - better than all the collars before, is the HALTI (dev. by Roger Mugford) or "gentle leader". It is similar to the halter for horses - and the training is done with the regular collar, better harness, and the Halti - with the Halti you always have "control over the head" by SLIGHTLY moving the head in your direction, use words such as "look, here etc.". Halti works best for dominance control and as well with not-so-selfconfident dogs. Halti is not for puppies but for youngsters and adult dogs.

3. If you want to take your dog with you everywhere and want to travel, you should start at puppy age getting the dog customized to motoring, inhabitation in restaurants, visit of department store, pedestrian zone etc. . 
The puppy must learn that nothing bad can happen in your company, no matter wherewith and where you are. Do training such as elevator driving, committing of various floors (glossy floors, mirror reflexes etc.) and get your dog accustomized to background noise (traffic noise, music, 
loud speakers etc.)

Extracts - some advices out of books of cynolog. authors. 

HUNDE ERNST GENOMMEN (dog's taken for serious) - of Eberhard Trumler ( +) 

Eberhard Trumler has spent all his life with the type-adjust behaviour of pack-living dogs - domestic. dogs, hybrides and wild-living dogs; but less with dogs training. Nevertheless, the natural dog-behaviour is an important basic condition is for a type-adjust raising of a puppy and therefore great benefit can be taken from reading the books of Eberhard Trumler.

development status:

characteristic-development-phase ( 4. - 7. week of life ) with the breeder

 socialization phase ( 8. - 12. week of life ) with the dog owner 

Hierarchy-phase (13. - 16. week of life ) 

pack hierarchy - phase (5. - 6. month of life ) 

aggression-drive, species-preservation etc. (pg. 154 ff. - 194) 
aggression behaviour can - at least transient - being increased or decreased by certain experiences (predominance/subdominance). For the good-natured dog a human is a kind of "high-in-hierarchy" = top-dog. If a normal dog bites a human it would mean biting towards a high-in-hierarchy-dog and a normal healthy dog would only show up with this reaction for good reasons.

The "alleged- so- aggressive- male dog": males have normally a generalized-by-nature instinct for care/maintenance-need conc. puppies (the child-schema - Konrad Lorenz ) and this is universally valid and applied on all creatures which show the infantile characteristics (in relation to body big head, roundish figure, round great eyes etc.). So in Wolfswinkel (research station of E. Trumler) they've  raised orphane-cat whelps with the help of a male dog. 
If possible, one should include the male dog within the whelps care; the whelps would surely proficiate therefrom.

True aggression in dog-fights is relative rarely shown at good-natured dogs, if socialized properly from puppy-age till adult age and accustomed to other dogs company. 

Chase- and prey-instincts have nothing to do with aggression.

A few basic rules: 

Normally male dogs will never injure a bitch or puppies / young dogs (till appr. 6 mths.)
The male dog can be that much under the influence of a bitch in season that the usually good control (bite-inhibit.) might not work and the male breaks this basic rules. 

Each newcomer added to a pack or other variations could change the pack's hierarchy too.
Equally dominante characters living in a pack arises as well the risk for "leadership-fights".

For puppies and young dogs I would recommend to "introduce" them to other animals, such as cats, horses etc., as the more other species they get familiar with from the start, the less problems would arise with the adult dog.

Notice: the aggression-drive is a normal instinct; to avoid "explosions of aggression-drive" various training, to play with other dogs etc. are useful. Avoid inperfected socialization, look for puppy-play-groups as well as contact with good-natured dogs of any age and size and different environment amenities .
Try to avoid contact with rowdies or dogs, disturbed in behaviour as negative experiences could provoke negative reactions (fear-aggression) in a puppy or young dog. 

If the dog owner ascertains an arising aggression readiness, one should try by training to "work against "  that, e.g. correlatively play, work, training. Especially playfully duel for subjects, playfully fight etc. are suitable to get dosaged rid of aggression. No normal dog will attack a pass-by stranger and bite. A normal dog will always give signs of alertness (growling, showing teeth etc.). Battling is matter left to the decision of the top-dog, in this case the dog owner.

In the present time we need - even more than ever - 
clever, selfconfident dogs of good character - 
but no aggressive, fearful-nervous animals.