Shaykh al-Mashaikh Haji Imdadullah mohajir makki (Allah have mercy on him) said,
‘Keep away from the company of Sufis that act against the Shariah.
Meet other people with good manners only as required.
Consider yourself to be the lowest creature.
Do not criticize anyone.
Speak with compassion.
Love being silent and alone (khalwah).
Keep your time well planned.’
Taleem ud deen, page 227
(The edition by Maktaba e Rehmania, Lahore is the best currently available. It has explanation and translation of all Arabic and Persian quotes in footnotes.)