I started by mouth, found that my mouth would be dry within minutes and my meditation would be ruined
then I moved to just the nose because it was simple but it took too much thought
doing some more research I found that breathing in through the nose and out through the mouth is best because its our natural breathing pattern. Try what you will but I found that after using this method for awhile, and just letting your body do the work and not the mind, this can be a very natural, quiet, and quick way to get into deep meditation with the least amount of breath used.
I think ultimately it dosnt make a hole lot of difference. I think the 'standard way' if you could call it that would be in thru nose out mouth, pausing in between, breathing for about 4 seconds each way.
There is also G breathing (was on the sacred G site) which is in nose, out nose, in nose, out mouth, in mouth, out mouth, in mouth, out nose, in nose, out nose, in nose out mouth, in mouth, out mouth, and repeat 3 times.
Generally, you will get light headed from any deep breathing. if you get light headed your doin fine.
take some deep breathes to get you relaxed like 10 3 sec in and out breathes, on each in and out count down to 0 (i.e. breathe in (10,10,10) and breathe out (10,10,10)... in (9,9,9) out(9,9,9) etc...)then tell urself when u reach 0 that you will become very relaxed, after that just let your breathing go and dont control it, then just focus either on ur stomach going up and down or the rims of ur nose feeling the breathe going in and out. There are other ways on getting "there" but those are just a few that i use.
U may encounter problems like dry mouth or w/e but as u start getting more habitual with it things like dry mouth and swallowing wont bother you anymore.
i like to meditate lying down, but for longer ones i sit on my futon couch with some pillow support on my lower back, its important tho that once u sit or lay to manage thru the discomfort so u dont spend the whole time movin around.
if u experience pain, just analyze it, mindfully observe it and soon its not even pain anymore... ull see... now if the pain becomes too unbearable come out but be mindful when coming out. Eventually ull get thru it and have your own way of doin things, but these are my tips to you.
heymartin the breathing part of meditation is important but as you progress you will concentrate less and less on breathing and more on what you are seeing and feeling when you reach a deep state.....i breath solely through my nose starting with three deep breaths to start....as you enter that peaceful state you will notice mainly two things one...your breathing will become more and more shallow to the point where your barely breathing at all and you become less and less aware of it so dont concentrate on breathing at that point just go with the flow....second....and this is the really cool part after about 20-30 min or so listening to holy harmony you will notice that your mind is completly awake but your body is falling asleep....you wont really feel anything from the neck down and youll notice your entire conciousness and awareness has moved completly to your head....from there you will become aware of things directly around you....after that the experiences will increase accordingly.....everyone has thier own way you just need to find yours....and you will keep at it!!!.....Sol