Becoming lucid is more about awareness than RCing. RCs are worthless if you're not aware enough to test them, so practice looking around the day and spontaneously thinking, "hmm, I could be dreaming right now". Then do an RC.

If you plug your nose in a dream, you are still able to breathe through it. That's a very reliable RC.
Another is checking out a digital clock a few times in a row (this is useful if you have a false awakening and you've got a clock right at your bedside). Usually in dreams, alarm clock numbers change with every glance. Look at the clock and then back again. Do this maybe three times, and the numbers, if you're dreaming, will probably change.

I suggest doing an RC every time you wake up in the middle of the night, and before/after you get into bed.

I'd say DILD is most possible for you if you practice RCing and awareness throughout the day. It sounds like you are making good progress on WILDing too, though.

For the dream signs, you just have to memorize what they are. When they begin to appear more and more in your dreams, it's easier to remember them.