Here is one of the articles on DEILD, and there are a couple of others that simply call it “chaining.” I’ve used DEILD a lot recently, and really the hardest part I’ve had is training myself not to move. I don’t concentrate super hard or anything like that, though I might start to imagine my next dream. I’ll focus on feelings and other things like that until they actually begin to manifest.
Sometimes my mind does get a bit hazy, but I’ve found that simple mantras like “I’m dreaming” repeated over and over make it easier to keep up my concentration. Really the hardest thing for me is training myself to not wake up.
I hope that helped, let us know if you have other questions 