Buoyancy control is the divers best friend, and often the inexerienced or unskilled diver's biggest concern. 

We do not dive on our knees so are extremely unlikely to find that we have to deal with any real problem which occurs whilst kneeling. True proficiency in a skill such as mask clearing can never be attained whilst kneeling as the demands of real diving require the ability to react to a situation which occurs midwater.

So stay neutral and still in the water column. Sounds simple doesn’t it? But how still is still enough? The required level of precision in buoyancy control of course varies with the demands of the dive (technical diving which requires decompression understandably requires much greater control) but from personal and team safety to efficiency and marine conservation, buoyancy control should be considered as the primary platform upon which all diving skills are built and a responsible diver should aim for as much control as possible.

To assess your buoyancy control, descend slowly adding gas to the wing where necessary to remain neutral throughout the descent. A new recreational diver should be able to stop within 3 meters of the bottom and float for intervals without having to fin, use hand movement or add/remove gas to maintain position. A more advanced diver should be able to exercise greater control than this. For some demanding dives in very silty or delicate environments less than a one meter window of movement may still be considered excessive with much greater precision required.

The first and most immediately effective tool that we can use for buoyancy control is our breathing but adjustments which are made quickly via lung capacity should be rectified by changing the volume of gas in the wing at the earliest opportunity.

A diver should consider when diving whether he/she has to breathe particularly shallowly or deeply to maintain position in the water column which is neither efficient nor comfortable long term. If this is the case then buoyancy is too dependant on lung volume and changes should be made to BCD content to address this.

For instant feedback, breathe in deeply. If you start to rise immediately then you are a little too buoyant and should adjust. When a diver is neutral, a deep breath in will start a slow movement in the water column which will accelerate as gas in the BCD starts to expand. If a deep breath in does nothing, then the diver was slightly negative at the start of the exercise and was probably running some buoyancy on lung volume already.