Return A is a glitch in which the camera stays positioned behind Link as if you were L Targeting. While on this state, you can delay getting items such as buying beans. Also you can't pick up things like a Heart Piece from the floor. To get Return A, you must press the L, R, and View button all three at the same frame as source of damage hits you. This can be really precise due to the View button being a touch screen button.
Performing the same trick again while on Return A, will put Link in first person mode but while also being able to move, roll, attack, etc. Commonly called First Person Glitch (FPG for short). The hookshot gains additional properties while in the first person glitch state, check out the Extended Hookshot page for more information.
There are several method in which you can perform Return A and/or First Person Glitch.
Put down a bomb and hold the view button until you reach the first big red flash frame, get into home menu and release the touch screen button as you return to the game. Buffer one more frame and hold L + R as you unpause. Repeat these steps to get First Person Glitch.
By shielding the rolling spike logs you are locked into shielding. Just press C-Up (View-Button or Pictobox) at the right time and you'll get FPG.
This method is similar to the spike method because you shield continuous damage, but instead of using the spike bar, we use bombs. Pull out a bomb, shield drop it and pull out another one immediately. Make sure that there is enough distance between the bombs so that the first one doesn't make the second one explode. Position yourself between the bombs and hold R and View. As the first bomb explodes, release R and a tad moment later stop holding the View button.
By doing Return A and buying a magic bean from the bean seller, you will delay collecting the magic bean. If you open the chest before collecting the magic bean, the content of the chest will be overwritten and instead give you a magic bean. Then you will receive the magic bean you bought earlier.