Hey Aspirant!

There is no perfect strategy for anything. All you can do is, work until you find out what strategy you are comfortable with. Start by being consistent in your studies and practice a lot of sample question papers. There is no shortcut to success so, make a plan, look into which topics are more important, work upon your weaknesses along with polishing your strength. Give yourself a target and try not to lose your motivation through the entire way.

There are many reference books in the market for almost every competitive exams. However, if you can't find one for your desired exam, you can always opt for ones that are for a very similar course with just a slight change.

You can go for Perkins, Fossen, SK Ghosh, Garry Nicholas, etc.

Hope it helps.