I would say that knowing the intent is a good start!
Really, if you are mindful, it practically shows you on its own.
The biggest foe is pride. If it helps, look at yourself alone as being truly wicked and perverse. Strange as that may seem, it does help. It is very easy for someone who has made a lot of progress to think they are something. This in itself is also a type of defilement of the heart that nudges us off the mark.
But yeah, knowing the intent might be the most important thing.
The goal of the hesychast is to eventually pray unceasingly, that is, to always be mindful of God. Jesus did say, "blessed are the pure in heart, they will see God". That being the case, heart purification should be a lifelong practice.