All theee of my horses ride in a hackamore, they all used to ride in bits but they were very unhappy so I switched them and it has helped a lot!
I use a Little "S" Hack on my TWH and KMPH. I have taken the plastic tube and wire off that is attached to the shanks underneath the chin and replaced it with a rawhide bit hobble. After some usage the wire was breaking at the bends. I have also used a sidepull with great success on my APHA. There are sidepulls that have incorporated a snaffle bit, too. All are great tools. The rawhide noseband when moved side to side helps to get your horses attention.
I use what I call an "s" hackamore on almost all my horses! It's much smaller then a traditional hackamore which has a very long shank, which makes it hard if your horse doesn't neck rein well
I don't currently ride any horses who use hackamores, but I've seen many successfully move from simple snaffles to hackamores.