Hi Natalielouise,
We use the t-touch method of stroking the lead to encourage him from stopping pulling etc.
https://youtu.be/Yl8iq39sibwThis is the YouTube link to it. Our trainer always taught us this way and it works really well for us, especially when ours decides to anchor himself to one spot.
On top of this, we too, treat when he is loose lead walking. To give you an idea of consistency for some dogs, we still treat for loose lead walking and Leo is 11 months old, although the treats are not as consistent now as they once were. He will often walk beside us, looking hopefully up at us for about 500yds before being offered a treat. Important thing is to stop, get him to sit, then give the treat, and walk on. We find that if we give him the treat whilst walking, he starts to pull the minute he's been rewarded for walking nicely.
We've also embedded a 'here' command to walking by our side. We started this by showing Leo the treat we had for him, asking him to 'watch me' which basically means 'make eye contact' and I bring the treat to my chest so he continues this watch, then treat after a short while.
Other than that, I do try to give our pup the freedom to have a bit of sniff time where I can, I feel it is important for them to learn about new smells and scents etc but also that it is on your terms.
I have also been taught that dragging them away from something entices them to go back to it again, as it is the classic case of 'I'm not allowed to do it, therefore I will do it more' so having a bit of patience, ignoring the fact he is not doing what you want him to do then praising him when he decides to walk again is the way forwsrd.
I'm certainly no expert and am still learning myself however these things seemed to have worked really well for us, on Leo's usual everyday walk he is as good as gold on the lead and we are starting to make progress in new places too.
I'm sure you will get some more really helpful advice on here but hope this helps a little bit