The Hebrew word for separation is p'rishut. P'rishut translates also as abstinence.

Fences exist in life for many reasons. They are there to establish boundaries, whether it be for the purpose of property lines, construction zones, or to protect innocent people from certain harm.

When we separate ourselves from things that are potentially harmful, we have a space in which we can reside safely and grow without threat. While we may walk a fence line and think there is no good reason for the fence, the fenced area is merely a buffer for what lies beyond. We must be certain that this separation is necessary and accept its purpose and authority in our lives.

This meditation can be used as a tool to focus your mind and soul on the fences in life that you have erected for soul-safety.

(Note: For more information on meditative techniques, see the source Jewish Meditation by Aryeh Kaplan.)

Take a seat upon either a carpeted or uncarpeted floor. The goal is to find a firm seat in a quiet place. First, take a few deep breaths. Deep breathing brings oxygen to your brain and helps clear the mind. Close your eyes. Continue breathing until you feel relaxed.
The focus of this meditation is to help you visualize the fences that are set up in your life and to embrace them as safety barriers to your soul.
Using a verse from Psalms 119:37 for meditation, choose whether you will say the Hebrew or the English. Repeat it in your mind until you are comfortable with it and can let it flow freely in your thoughts:

הַֽעֲבֵר עֵינַי מֵרְאוֹת שָׁוְא בִּדְרָכֶךָ חַיֵּֽנִי

(Ha'aver aynai meyr'ot shav bid'rachecha chai'yeyni)

Turn away my eyes from beholding vanity; and give me life in Your way.

—Psalms 119:37

Imagine as you repeat this verse, either aloud or in your mind, that you are walking along a fence line. This fence stretches out over the distance before you; though it meanders, it is secure and well-maintained. Try, as you repeat this verse over and over, to experience the safety you feel next to this fence, protecting you from dangers on the other side, known or unknown.
Visualize your slow movement along the fence line while repeating this psalm. Let the words become part of your steps ... match the words to each step. Focus on the security of your steps, knowing you are safe because of this barrier in your life. Connect this fence in your mind to a fence you have erected in life to protect you from a known destructive behavior. While you might be tempted to consider what is on the other side of the fence, focus your mind on the side you are on. Find contentment and comfort in that safety and assuredness that Hashem has helped you find. If you find you are struggling with a fence you have erected and want to tear it down or hop the fence, concentrate even more strongly on the need to stay on the correct side. It is okay to realize the struggle and acknowledge it; however, in the end, you are a master over it with the help of Hashem.
As you end the meditation, carry with you the visualization of this meditation. When you encounter a difficult moment, remember your fence. If you feel your fence has been compromised, bravely mend it and return to this meditation to recall the peace and wholeness that separation brings as well as safety from sin.