The Importance of Focused Dhikr: A Path to Spiritual Concentration (Words of Sheikh ul Islam Mufti Muhammad Taqi Usmani)

The elders(Akabir Auliya ALLAH) have advised that it is better to designate a specific place for the remembrance (dhikr) of Allah, so that when you sit in that particular place for dhikr, your thoughts remain focused and do not become scattered.
Whatever words you are saying with your tongue, say them with full attention. For example, if you wish to say “Subhan Allah” (Glory be to Allah), then while your tongue is saying “Subhan Allah,” be mindful that you are saying it.
When you say “Alhamdulillah” (Praise be to Allah), focus on the fact that you are saying “Alhamdulillah” and that you are glorifying Allah the Exalted and praising Him. When you say “La ilaha illallah” (There is no god but Allah), think about the fact that you are saying “La ilaha illallah,” and this is your proclamation and affirmation of the oneness of Allah. When you say “Allahu Akbar” (Allah is the Greatest), be conscious that you are saying “Allahu Akbar” and declaring the greatness of Allah. In this way, try to focus your attention on the dhikr.
In the beginning, when you try to focus, your mind may wander elsewhere. However, when you become aware of this, bring your attention back to the dhikr. Even if your mind drifts again, bring it back. By practicing in this manner, through the mercy of Allah, there will come a time when your attention remains fixed on the dhikr, and thoughts of other things will become subdued. However, this will only happen if you dedicate time every day and regularly engage in dhikr.
(Dars-e-Shu’abul Iman, Volume 1, Page 45).

(Selection by Muhammad Faisal Sahib)