Hakim al-Umma Shaykh Mawlana Ashraf Ali Thanawi (may Allah have mercy on him) wrote in the preface of the book Munajat-e-maqbool,
“In case of dua (supplication) few errors are taking place. That are;
1. To supplicate (dua) only when faced by an adversity.
2. And on these occasions instead of using the supplications told to us by Allah and holy Prophet (Allah’s blessing and peace be upon him), we go for new and innovative litanies (wazaaif).
3. To supplicate without true yearning, devotion and concentration.
4. To lack the conviction and aspiration that the supplication will be accepted for sure.
5. To make haste and expect immediate response.
If there is delay in its acceptance to be disheartened and abandon making dua.”
Munajat-e-maqbool, page 3-4