Simply by the habits you repeat every time you meet with your horse. You do the same things over & over again pretty much the same way.  The horse being a conditioned response animal will learn your habits and develop his own set of automatic responses to your cues if you repeat them consistently.  Consistency is a key to the development of your partnership.  Your horse does not know when it does not count.   This means that you must make your communication simple and clear for the horse to understand, and always be consistent.

Think of your horse as if he were a kindergarten student from a foreign country.

Then as a teacher you must teach this foreign kindergartener a language so you both can communicate.  This is done through your cue system and literally thousands of repetitions of each step from #1 to the goal of the partner responding perfectly to your requests.  A partnership is going to require more understanding, love, kindness, trust and patients from you. Remember a partnership is a relationship with another living being with a set of four basic characteristics that God has given to the horse to govern his behavior:

1.Flight from Fright

2.Heard & Pecking order

3.Laziness

4.Stallions desire to breed

The above-mentioned characteristics are in every horse and each will be expressed at different times. Understanding they are there will help you as you work through your lesson plans with your partner.  If the system you have chosen is positive, loving and friendly you are on the way toward developing a partnership.

However if you don't have any particular plan and you are finding that what you are doing now isn't working or your horse is getting harder to control even after trying more severe bits, gimmicks or harsher methods you should stop and re-evaluate your current plan and make a change to a friendlier method.
 One thing that you can do is leave your temper in the tack room and take out a double dose of humor.
If you are having trouble getting the horse to do what you are asking, back up in the lesson plan to a place that you know the horse understands the cue and can do the step. Start repeating that step until you get improvement and start trying the next step toward the Goal.   If you are not famillier with setting Goals and working step by step perhaps the following information will be helpful.