Reins are the direct connection between your hand and the horse's mouth, and depending on the horse, rider and riding style, there are many different ones with different advantages that can meet your requirements:
The end of the reins that is buckled into the bit can either be a buckle, a ring (Warendorf reins) or a metal carabiner. The latter are of course particularly easy to change and are ideal if you frequently change the bit or want to use the reins on different bridles.
The end of the rein running from the bridle goes between your little finger and ring finger and into your hand, which should be slightly clenched into a fist. It should then come out between the thumb and index finger. Place your thumb loosely and lightly on your fist. Place the ends of the reins over the horse's neck on the right side so that they hang down between the reins and the horse's neck. Hold your hands upright with your thumbs on top. Both hands should be about a fist's width apart. Your forearms should form a straight line with your wrists and be slightly bent. To perform a reining action, you only need to move your fingers and/or tilt your wrist slightly upwards. Then bring your hands back to the starting position.
You can perform a half halt with any type of rein. The purpose of a half halt is to attract the horse's attention, to make it change gait, to slow it down and/or to make it push its hind legs further under the body. To do this, first sit very straight in the saddle. You should imagine that you are reaching the sky with your head and to the ground with your feet. By stretching your body in this way, you give your horse weight support on both sides. Then, increase the pressure of your legs around the horse's belly. These two aids cause your horse to push his legs further under his body. This gives the horse the impulse to move forward. Now you should counteract with the reins just enough so that your horse goes at a slower pace or changes gait.