I guess in music producing there is no main rules how to achieve good sound etc ))...
For more ambient stuff i <3 to use NI absynth5 i heard that albino is good for those sounds too. You need to think about which sound will be main in your tune... if these will be drums & bass then you want highpass with EQ pad little bit more (loosing low freq from pads etc will make room for drums & other low stuff) but if atmo will be main than you can highpass it and left some mid range in it . I hope you understand what i think , cheerz & good luck in production
i'm fairly new to the whole ambient dnb thing too, but for my latest track (check out my sig, may even give you some ideas) I put together some loops and actually sampled background audio of youtube videos, mixed with a bit of live guitar.
What i like to do is, duplicate the channel and the midi/audio (whatever your working with) and then pan one slightly to the right and the other slightly to the left to make it sound a bit more atmospheric. Then i would add a nice bit of reverb on top, i do this a lot, it has become a habit lol
layers and slow automation/LFO, and drenched with reverb, vocoders are quite nice aswell, for ambient its more about texture than chords imo, little ripples moving thru the sound accross the freq and stereo spectrum are what makes a good ambient soundscape, lots of ways to do it, but automation and LFO's are the key, keep things subtle and keep things moving
i mite do a tut on this when i put together the sample packs in a few weeks, stay tuned
Vocal pads, Hands down are one of the coolest for me, get a nice vocal AHH or OHH sample and autotune it so its perfect then blur it/drench in reverb and save that as a sample.
Then chuck that in a sampler, you will have better range if you use many vocal samples spread over the length of the keyboard.
These are harder to come by unless you get some pretty lass around and record her singing all the notes needed. Having many samples means each one only needs to be pitch shifted a small amount.
Once you have your basic vocal pad sound do all the standard pad tricks to it stereo detune, dupilcate, reverb, delays and so on.