If I know what I'm doing? Hmm, I like to think that I can by paying close attention to the problem itself. Every organisation is unique, and though their problem sounds general and well-defined, it usually isn't. So as part of scoping, you need to dig further in order to gauge the actual problem - you may even realise that it's a symptom of a deeper problem in which case training isn't always the solution. This does mean that you have to immerse yourself in the organisation to understand the culture, biases, IT system, branding, language and so on - all this will also feed into your final design. And build relationships; rarely what people tell you at first actually match up with the real problem.

My rule is to start from first principles and work my way up as logically as I can. This helps to cut through the bullshit - yep, I agree with you that there is too much of it in L&D. However it's also useful to know core pedagogy theories and the latest fads, because it will help you speak in their language. Some of them are genuinely useful, but I find myself drawing mostly from design and behaviour science.

Digitalisation is a serious strategy though. You will be surprised at how dated some systems are in the biggest companies, and the amount of reluctance to adapt in the workforce. The mistake most companies do is to rush with digitalising their training, when there does need to be a proper transition sensitive to the workforce's needs and perceptions.

Although I've sung praises about eLearning here, personally I prefer blended learning - but the best ones require skill in creating the complementary digital component well.