Procedure to save clients database and vital information in company

Dear all, If any employee work in our private limited company, learn all the tricks of trade, have all our clients database, trade secrets and other vital information about the company. In that case how can we restrain them from using the same when the said employee leaves the company and join another company or develops his own company using our above trade secrets, clients and other vital information. In this case which agreement can be legally helpful to save the interest of company: a) Non Disclosure Agreement, or b) Non Compete Agreement, or c) Non Solicitation Agreement, or d) Any other Agreement which you deem fit legally ????