As much as it takes to summon a useful emotion.
I shapeshift easiest when I’m angry, in pain or highly elated (and this often costs only the energy generated by the emotion) and less easily when I’m listless or somewhat feeling “down” (in which case it could take me hours to achieve a shift effectively). But this will definitely depend on the person, what they resonate with, and what techniques prove to be most effective. For me I’m an emotional person and I resonate with dragons, so often I use emotions to become (even just spiritually) a dragon.
Just a weird link.I wanted to.post to creep people out:
http://krqe.com/2014/02/07/recent-nm-skinwalker-photo-ignites-fear/
That’s another question: can I become a skinwalker?
Have a look at my intense journey into physical shape shifting I’m still on this journey myself.
I was reading that earlier, very interesting. Mind dm’ing me the process to make chakras into moon chakras?
Yeah sure
Learn to channel a tons of energy through your chakras and intend for it to increase the resonance of your body’s vibration, you will dematerialize into etheric matter, from here you can teleport, time travel or shape shift, or just learn to etheric project, change the shape while out and then reenter. if you approach this stuff from a mystical magic way, it will take years, these powers are scientific
Not everyone wants to, though? I don’t really see any use in it, in terms of shapeshifting into a non-human form and being observed on Britain’s MANY CCTV systems etc… I can honestly see it causing Firestarter-levels of problems tbqh. 
Non-human animals have zero rights, in practical terms (I don’t support this or completely agree with it), so why trade down the social scale?
Shapeshifting mentally, or in the astral realms, that’s another story. 
The ability to transfigure into elements is also taught in core shamanism, is arguably linked to shapeshifting for purposes of power etc., and that’s a good skill to have, especially when combined with ayurvedic healing (perhaps also Chinese traditional medicine. but I don’t know enough about that to speak from experience).
It doesn’t have to be an animal though right? What about shapeshifting in a demonic form?
Well I don’t personally want to chance that the Met police have a special “they’re a demon not a gorilla” clause written into what they can taser and ship off to DARPA/Porton Down or whoever, when I decide to go on a 12-foot tall muscle-bulging horned demonic rampage down the high streets of Britain…
It’s like flying and other flashy siddhis, why draw attention of a kind that will almost certainly bring more problems than gains, simply to be ale to say you did it? I don’t need that level of proof since my “evidence files” are already jam-packed with things that blew my mind. JMO though! 
The process of learning how to perform these skills may be valuable in and of itself. The insights gained, the new understandings achieved may help one’s Path immensely.
Very true, though manifesting from thin air can be done for real and actually be useful.
Other miraculous siddhis fit in that “useful, and less likely to cause problems” category as well.
Now I agree with you @Lady_Eva, because I too live in Britain to be honest when ever I do any of my shapeshifting settings I have to climb and walk for hours to a very high mountain with no CCTV whatsoever.
So it can be a bit of a bother, the reason I believe shapeshifting is a great tool, because imagine mastering changing to whole other species.
We have full control over our selves, any deseases can be eliminated by shifting the cells, I honestly believe this is a huge key in certain parts of magick.
Manipulating the manifest material reality through will would cover it more comprehensively, maybe, that also includes the (to my mind related) manifesting and spontaneous healing, both things that transcend the usual causal routes. and I’ve found that mastery of both INCREASES subsequent ability to perform things using normal causal routes, as well.
I’ve never actually tried to shapeshift so I dont know how much power it would take. I accidentally made myself invisible once at work. I was trying to do aura to shield myself and lost concentration and I felt i used too much power and something “go wrong”
My supervisors constantly kept forgetting I was there even though i sit right in front of the office. Theyd look at the roster and not see me even though my name was right in front of my face. I’ve been trying to retrace my steps and see what i did ever since!
" when did you get here? Did you come in late?"
“No i’ve been here all day!” 
I would have used the opportunity to make the best farts in this world.
Have any resources I can sift through on that?
Only my own experiences really, soz.
It’s like reality isn’t crazy about you going into full-on god-mode so will put you in god-mode lite by delivering things by highly improbable but still JUST normal and conventional routes so you don’t upset the apple cart.
It also gets a lot more responsive to your wants.