UPSC is a exam all about dedication, hardwork and startegy. Some students crack it wihtout coaching by following basic strategies. One can ace any exam without coaching. As everything is very easily available on the internet. The first step should be to know the exam pattern and syllabus. Once you have rounded the pattern go for syllabus and buy books which are mentioned on the internet. Make a time table for study and divide the subjects with comfortable gap. Create a basic schedule, Start slowly dont exhaust yourself. Every day solve topics and make notes. Notes play a major role in revision and saves your tim. Pay attention to topics which trouble you and refer other books or some youtube videos to clear your doubts. Once you are done with your syllabus solve mock papers. Make a habit of reading, Read newspapers, inspiring quotes and listen to peaceful music.Update yourself according to your present. Always remember key to crack any exam is peaceful mind and dedication to acheive the goal. All the best!