While I have seen decent shooters put both toes on the oche, you do have to turn the body a bit anyway to get the shoulder out and towards the board or you must learn to throw with your forearm at an angle over your upper arm. (Dartplayer.net)

You could just stand at the oche and throw your three darts but this is "throw and hope". Before throwing a single dart, it is vital that you learn how to stand at the oche line. Why? Because this will ensure the most effective and accurate release of each dart as it leaves your hand on its journey to the dartboard... (Darts: Skills - Tactics - Techniques)

As the darts players of the future line up, waiting silently for their turn to toe the oche, founder and former darts pro John ‘JJ’ Gibbs is reveling in the success of the country’s first darts “School of Excellence.” (Katie Durose: Superstars of the Oche)