I've noticed exactly the same with me. I got to know about the LOA through Joseph Murphy's book and manifested lots of things through simple affirmations and visualisation but it was always some kind of recreational visualisation and effortlessly. Since I've tried to read and learn more about techniques and all it has just blocked things. I think for me it is best to stick to the basics, but it all comes down to finding the technique that works for you and it might not be the same as the next person. I don't think using a hundred different techniques at the same time is making things faster or more efficient, on the contrary it makes attachement grow because you are always self conscious about the process..
For me it seemed like I manifested easier before I was deliberately using the LOA but then again I havent been deliberately using it that long. I think Im thinking about the outcomes too much now that I know more about the LOA. I dont have any anxiety over it but I cant stop thinking about what I want to manifest in all areas of my life so maybe i am attached to the outcome and I need to think about other things but its hard since im trying to manifest for every area of my life since my life is kinda blank now.