how can I prepare for ias while studying at home without any coaching

You can go through the below points -



Smart Work:  If you want to be successful in the UPSC IAS Examination then you have to put long hours into preparation.



Read Only Whats Absolutely Essential: We refer to every candidate on standard books.



Test Yourself Constantly: Testing yourself is a technique to evaluating yourself, this activity shows to candidates the real image.



Choose a Reliable source of Study: A Reliable source of Study is an important factor.



Outline the syllabus: You have to make syllabus outline which provides help to a candidate in analysing the important topic.



Make handynotes: Candidates nowadays can be pretty demanding about the teachers PowerPoints, lecture notes, and other hand wrote forms of the content presented in class.



Enjoy your preparation: The examination preparation of UPSC IAS exam is much lengthy as compared to the other competition examination.



Time management: Time management is an essential skill which is necessary for candidates, You must develop the time management skill before going to appear in the examination.



Good  English approach & Self Confidence: English language and self-confidence are must for every candidate because it is a key to success in the UPSC examination.



Hope this helps!!!