Like most things in the dog training world, there are several opinions on how to toilet train. Here are a few general tips.
As they grow, healthy puppies naturally do not want to toilet where they eat, sleep and spend most of their time. Use this to your advantage.
Never give them free run of the whole house - it's too big. Sometimes even free run of one room is too much space. Crates, play pens, or baby gates can be useful tools to block areas off. Actively supervise or put them in the smaller space and take them out A LOT.
If the mother dog or later on, the breeder, does not keep things clean, these puppies may never learn to distinguish between the bed, dinner table and the bathroom so "go" anywhere or even may try to clean up after themselves. Some owners may have a huge advantage if the breeder has put the time in, they may come trained and others may have a more challenging road ahead.
Young puppy bladders are tiny. Their muscles aren't very strong and their kidneys don't yet concentrate urine like adult kidneys do. This means they basically have the bladder of a gnat. On the plus side, it gives you many opportunities! As soon as they wake up, after eating, after drinking, in the middle of a play session, after something scary or exciting has happened, after new people enter the home, as soon as they get out of the car - get the idea? Puppies who aren't let out to the toilet may get to the point where they can't hold and are forced to toilet where they are which can undo all your hard work so keep it up for longer than you think you need to.
Puppies are vulnerable when they poop. Once settled in to home, pay attention to eating and pooping times, this will help you form a regular schedule and you'll quickly learn when it's best to take them out. If you notice nose down sniffing, circling and tail up - they are likely looking for the right spot to go so get them to where you want them asap. Feeding a quality complete diet will help here too.
Accidents need to be cleaned up with a deodorising enzyme type cleaner - they will keep going back to toilet where it smells like a toilet and some cleaners may mask the smell to humans but not for the exceptional canine nose.
If you yell and make a big deal with the accidents at the time of toileting, they learn to not toilet in front of you or even to be scared of going to the toilet at all.
If you yell and make a big deal afterwards, you're too late. If you come home to find an accident and you get angry - the puppy learns that you coming home is the issue, not the toileting.
Keep in mind, puppies may learn where to toilet at home, but it does not mean they know where to go if you were at a friend's house so be vigilant.
It takes work, but is far better to put the effort in now rather than dragging it out over several months.
If they are house trained and they lapse, your vet is the first place to visit. Dogs and puppies can get bladder infections etc just like people can so if something weird is going on, rule out health issues first.
If you would like a more specific method tailored to your situation and environment, please send a message and I'd be happy to help! .