If we talk about the process of rehabilitation program of you we expect that you are going well through it. And now you are free to attain this facility. So outside the center of rehab and by facing the task of uphill by resisting your temptations to fall it back to the old bad habit of you. It is challenging for you bur there are some things which may be able to help you to stay calm in this case.
Change the friends you have
Because of people or company around you it might possible that you again start that habit or became an addict again. If you feel that there is a person who makes you a drug addict again then you may dump that person from your life if possible, remember that it is only for your own good.
Avoid old memories
That bar or balcony of your college, where you start to use any drug for the very first time. These are memories which you would realize that that were your good memories so these memories may also hunt your mind and remind your old good days with your friends. So you must move your locations to another place. Simply just move your house or residence to another location.
Have a plan to keep off drugs
The groups which may lead you to keep away from drugs or your old drug addictions which you are already stuck out from your life, I recommend you 2 groups which are Alcoholics Anonymous and Narcotics Anonymous, they might help you to keep your habits sober and even better, so whenever the craving of your drugs comes to you then you might be able to look your plans to stay sober and fight with your problems.