There are numerous somewhat more advanced kriyas with the subtle variations, which may, at a certain stage, also employ the use of mantra and bandha or other somewhat extraneous features in combination with the orbital/linear breathing routes, the purpose of whichthey can kind of supercharge the circuits you are working along energetically-speaking.
A sound starting point for any approach that seeks to awaken kundalini i think is some prelimary work on the third-eye/ajan chakra as this is master controller chakra.Seek to have some balance there already. Some approaches may not do this or emphasise it. I use the Satyananda approach; Satyananda in a very short space of time may have got this from his orginal teacheer/guru Sivananda upon leaving his ashram and then he may have made slight modifications or revisions to what the kriyas he did teach and publish based on his later itinerant wanderings and meetings with other yogis throughout India,the Himalayas( I have read that somewhere for sure) and possibly other parts of Asia.I believe it is the real deal or one of them or at least a good sound approach, let’s just say, but i’ve tired the basic linear- routespinal breathing before and it didn’t really work for me as well.The SRF maybe practices something like this.I could’nt realy comment though as I’ve never actually followed them or know what they do exactly.
Also it is often good to have some kind of mantra meditation to compliment the kundalini kriya because it helps cultivate the inner silence you will benefit greatly from in order for the merging to occur; of shakti,energetic potential with Shiva,pure bliss consciousness.It is an ideal marriage that is a recipe for the expansion of Consciousness.
Find the methods(or people although you can learn from everybody) that are useful on your own path ( don’t fixate on cults or groups or indivduals too much;don’t become depndent on guru-like figures) and you can dscardwhat is’nt so useful. The principles usually remain the same or similar;it’s just the methods vary.And the teachers teaching them will put their own spin on things but that is what you should expect them to and is a good thing.Somepeople talk about purity of lineage like that can ensure authenticity over time but that debate can sound a bit academic to me.