A good way to continually have an extra Life is as simple as Finishing Green Hill Act 2 (the Stage in which you play as "Modern Sonic") under "Play Game" in the Main Menu.

Simply finish that level without dying and you will have the ability to gain 1 Extra Life up any time you effectively finish that stage.

But always try using the Higher Ground for the reason that Level, in addition to while using "Sonic Boom" (Y - Button) to complete the Level
Rapidly, and you ought to have the ability to collect enough Rings not less than 1 Life up any time you finish that stage.