Hello and Welcome
Milo is now 13 months old and is only just learning not to pull, he still has his moments tho
I tried lots of different techniques and approaches before i excepted i had a weimaraner

what i have settled on is a halti which doesnt work just by itself so what id do is set off with a Heel command, as soon as Milo starts to go infront i turn on my heel and head for home, he will whine and fuss, but i do not turn around until he is quiet.
This gets repeated until he cottons on.
On our usual walk it takes 5 minutes to get to the field, the first time i used this technique it took nearly 40 mins

but my patience and consistency is definately starting to pay off. My ultimate goal is to have him walk on a loose lead using just a flat collar and no halti.
I would suggest if your dogs pull you take them out individually as you will be fighting a losing battle otherwise yes it will take alot of time,but it will be worth it in the end. I would also suggest that if you try this technique be prepared to walk all the way back home and try again later, I have walked Milo and because he didnt walk nicely at all ended up back home 20 mins into the walk, the concentration they use when you are training them can tire them out too.
Have to say i am very lucky as both the girls walk perfectly to heel on loose leads i would have had a nervous breakdown if all 3 pulled on their leads.
Good luck and keep us updated!