You're doing great, don't get obsessed about it and it'll be easier. As for which RCs work better, I suppose it depends on the person, and keep in mind that any RC has a non-zero chance of failure. My favourites are:

- plugging my nose and trying to breath. If you can, you're dreaming. This one has never failed to me yet.
- looking at my hand and counting how many fingers it has. If they look blur or difficult to count, or you have any number of them other than 5 (in my case ) then you're dreaming.
- Reading a text twice and checking that it reads the same

The last two have failed to me from time to time, but you can do any of them without people thinking you're crazy :p Do more that one check each time, because I suspect that subconscious mind tends to learn those tricks and improve the simulation of reality. Texts in my dreams are becoming pretty readable and make sense.

Remember, be patient because it's worth the effort. Chances are that your first dreams will last a few seconds after realising that you're dreaming because of the excitement and lack of control, but the sense of awe the first time you do a RC "just in case" and discover that the whole world around you doesn't exist is priceless. It's so... matrix