As you want to get the details of tips for self preparation of IAS exam so here is the information of the same for you:

Always rely on yourself prepared notes. Go through your short notes rigorously.

Prepare out short notes of important topics with relevant points and just before the examination rely solely on it.

Always rely on revisions.

Take a good sleep on the eve of examination. It is most important for your
brilliant performance.

Never go through any book on the eve of examination.

Don't read any new topic.

Don't get engaged with any confusing question or problem as your prior
investment (with studies) will only bring dividends to you.

Do not loose your confidence.