Hi, a feint dodge is used to confuse the defender and enable the attacker to get free. Therefore my 3 tips would be: 
1) Commit to the feint dodge - if you only half commit you will not fool the defence and it will not work.
2) Drop your shoulder the way you want to fake - this will only slightly move your bodyweight that way, but if your defender believes the fake they will fully commit and move their whole body weight making it difficult for them to recover. 
3) Drive hard in the opposite direction - once you have completed your feint dodge, push off your outside foot and drive hard in the opposite direction so you do not allow time for the defender to recover. 

The most common errors are that the player does not commit to the dodge or waits too long after using the feint dodge, thus allowing the defender to recover and remark you - these can be corrected using the tips above. 

Hope this helps.