The steps are basically similar but these are to be followed sincerely:

-First step is to go through previous year papers.

-Many magazines are specifically available in the market for GK and Current affairs. To enhance your knowledge in G.K. you can go through Manorma, India Today, Pratiyogita Darpan, Competition Success Review

-Under GK you need to select your strong areas first and prepare them quite thoroughly. Prioritize the preparation of GK as per your strengths. Business, Economics, Law, Politics, Sports or Technology might be the areas you are interested in. Prepare your favorite areas to the maximum level. This way you will definitely be able to boost your confidence and secure a good score.

-To check your level of preparation and to strengthen your preparation you are advised to take mock tests. It is very important to take online mock tests besides reading and grasping from different sources. Take the ones based on the actual Exam pattern.

There is no specific time to prepare GK/ current affairs but yes you must be well-versed with the last 3 to 5 month's current happenings around you.

Good Luck!