Hi and welcome! There are others here with much more experience than me but I get there impression there's not one set of "best techniques" that will work for everyone because people's brains work differently. Anything that gets you thinking about lucid dreaming and dreams regularly ought to help. I think with affirmations they have to be meaningful to you. Maybe someone will be along with some suggestions. Otherwise I'd keep experimenting with different things to find what works for you. I think it's important not to get bored with whatever technique you have.