I use martingales, but only because Grady's slipped out of a regular collar before.
However, I only use the martingale as a tool, I don't hold it up high to control like a "steering wheel." I have on occassion, but not normally, only when they get a bit dense and we're in a place where I need the extra control. Martingales, prongs and chokes all need to be fitted properly and used properly, especially prongs and chokes because they can cause damage if not. So, I'd suggest a professional trainer fit one for you, if you choose to go with one.
I tend to want to train rather than restrain. So, I use lots of treats and reward when they are in the proper position. Also, keep in mind WHERE you reward is key too. If they are in heel position and you reward in front of you, where do you think the dog will go? In front of you. And where do you think the dog will think it's supposed to be? In front of you. Because you've rewarded in that position, you've rewarded them for BEING in that position.
So, I only treat/reward/praise in the proper heel position. I keep the treat in my right hand and when they are in the right position by my side (I also wait for full focus on me for formal heeling, but dont worry about that for just regular leash walking), I put the treat in my left hand and sorta slide my hand down my side, down my leg and right to their mouth. This way they get the treat without ever leaving my side.
Takes time, takes LOTS of practice. And honestly, Rubi is a horrible puller, but I screwed up with her. I used a harness that encouraged her to pull. I rewarded in front of me rather than beside. I rewarded at the wrong times and I let her get away with it for too long. So, she is still a work in progress. Most of that is also because we lived in an apartment for the first 3 years of her life and all of her potty breaks were on leash. She'd pull to go pee in the woods. It became a hard habit for her. But, when we were in training classes, she learned a better heel and atleast now - she pulls forward, but checks back in all the time and gets into place. She's just a type of girl that has to go, go and go. LOL